'^?r: ^-.5oN\. ..^^—V,. r*^'lr"^. '.%£.■' ;■ . --r '■/,■■ '■ ■■A- m. *> / I. CRYPTOGAMIC BOTANY. A MANUAL OF CRYPTOGAmC BOTANY, ADAPTED TO THE REQUIREMENTS OF THE SCIENCE AND ART DEPARTMENT. ^-!BRAR*f ^EW YORK ^^ OAkOFs CHARLOTTE M. W. RQSS. Lecturer on Botany at Stockwell Training College and the Batters ea Polytechnic. ALL EIGHTS EESEEYED. LONDON : Published by the Author, i, Banbury Street, Battersea. 18 9 4. AsHFiELD & Young, printers, Bridge Road West, Battersea. !S=vv VORX PREFACE. This work has been chiefly drawn up from my notes of Lectures delivered at Stockwell Training College, and the Public Library, Lavender Hill. The material has been gathered from the most reliable sources, and frequent reference to Sachs' excellent Text Book, to De Bary's Comparative Morphology and Biology of the Fungi, and to the works of Strasburger, Bower, and Vines has been made. The chief aim of the book has been to reduce to a concise form the life histories of the various plant organisms, detailed in the Advanced Syllabus of the Science and Art Department. The special difficulty of young students studying for this examination is a want of the necessary time to pick out from a host of others the special characters of the species intended for detailed study ; this difficulty I have attempted to overcome, believing that when these types have been thoroughly mastered the larger works will be read with profit and pleasure. The book has been interleaved with blank pages to encourage students to draw^ if possible, from the microscope, the necessary diagrams for themselves, for a careful microscopic drawing is infinitely more valuable than a mere text- book description. In conclusion, I must add that Dr. Scott's and Professor Farmer's admirable lectures delivered at the Eoyal School of Science have been of great value in drawing up this little work, and that much of the information so gained has been supplemented by personal observation. C.M.W.E. December, 1893. CONTENTS. FUNGI. PAGE Saccharomycetes Yeast 1 Zygomycetes Mucor 4 ASCOMYCETES . . . . Eurotium {Mould) 9 ,» . . CoUema [Licheii) 16 Basidiomycetes Mushroom 13 ALG^. P110TOCOCCACE.E Protococcus 24 Zygnemace.e . . Spirogjra 27 FUCACE^ Bladder-wrack 30 MUSCINE^. • Hepatic^ March an ti a 38 Musci . . Funaria 50 LYCOPODIN^. Selaginelle.e . Selaginella 56 FILICINE^. Filices . . Aspidium 65 Class.— FUNGI. 0]?dei? X.— S£i.ccli.£i>i?onAycetes. Type.— YEAST (Torula) Sacoharomyces Cerevisise. Small round or ellipsoidal cells, having a diameter of about '0003 of an inch. Each cell is an individual plant which lives an isolated life. STRUCTUKE. A thin, smooth, cellulose wall encloses a cavity filled with protoplasm, and one or more vacuoles. According to Stras burger a nucleus is always present, but nuclear division has not yet bee a observed. The cell wall is very rarely coloured blue by iodine and sulphuric acid, and is considered a special modification under the name t)f fungus cellulose. Starch and chlorophyll are never present, the characteristic contents being a fatty oil. The protoplasm consists of proteids, the chief being '' Protein," a compound analogous to Casein. The chemical elements present in (1) Cellulose, are Carbon, Hydrogen, Oxygen ; (2) Protoplasm, are Carbon, Hydrogen, Oxygen, Nitrogen and Sulphur. The wall also contains minute quantities of Calcium, Potassium, and Magnesium. When growing in a liquid capable of ferment- ation, the Torulfe multiply very rapidly hy budding and abstriction. They require Oxygen for their growth, either free, or diffused through the liquid. EEPEODUCTION. Budding and Abstriction. Each cell gives rise to a minute protuberance (in some cases more than one) which grows rapidly ; after having attained the size of the parent cell it is separated by a septum of cellulose. This cell becomes detached after having developed a second generation of buds. When the growth is energetic long chains are formed. When the growth is slow, abstriction takes place before the '' bud" has attained its full size. Each cell can thus have an independent life, nnd repeat the process of budding. In rare cases the Saccharomyces multiply by spores or endo- genous free cell formation. The protoplasm divides into four masses, each cf which surrounds itself by a cell wall. These are set free bv the dissolution of the mother cell. Each of these can repeat the same process. The necessary cellulose, protein, and oil are manufactured by the yeast plant out of the nutrient fluid. DISTEIBUTION. Saccharomyces are believed to be always present in tlie air, forming a sort of invisible dust. They are cultivated in the process of brewing ; they appear in nature on the surface of fruits, causing a ferment- ation of their juices after they (the fruits) have been crushed. They appear as moulds on the surface of fermented liquids, such as beer and wine, causing further decomposition. They are the cause of the disease known as Thrush. Yeast cells growing in a saccharine solution cause fermentation to be set up. The sugar is decomposed into Carbon di-oxide and Alcohol. A minute quantity of glycerine and succinic acid are formed at the same time. The alcohol remains in the liquid, and carbon di-oxide is given oif. If the fluid be free from oxygen f ermentadoii takes place, but the yeast cells do not grow, they pass into a dormant condition and finally perish. Dead yeast cells do not cause fermentation. G^A^G'^^I^^Ml I^ Qy Type-MUCOR MUCEDO. This is a common mould fungus which grows on living plants, decaying vegetable substances and the surface of organic solutions (glue or saccharine fluids). The fungus derives its nourishment from the material on which it grows. DESCEIPTION OF A MATUEE MUCOE. The vegetative part — the mycelium — consists of copiously branched irregularly septate sacs, each of which contains streaming protoplasm and many nuclei. Each branch, whether septate or unseptate, is called a hypha. From these hyphse arise the straight, unseptate, unbranched, fruiting branches, called Conidiophores (or gonidiophores) which are also multinuclear, and in these the streaming of the protoplasm can be specially well observed. Each filament or conidiophore bears a globular head — the Sporangium. The conidiophores are an inch or more in length, and turn towards the source of light. The sporangium is round, yellow or brown, the contents being yellowish-brown protoplasm, and many nuclei. The conidiophore ends in the interior of the sporangium with a swelling like a ninepin. This swelling is called the columella. The wall of the sporangium is rough with minute particles of Calcium oxalate (Ca C2 O4). ASEXUAL REPRODUCTION. The contents of the sporangium (protoplasm and nuclei) gradually separate into a number of masses, each of which secretes a cellulose wall {free eell formation). The cells thus produced are termed ''spores"; these are the reproductive organs, and being produced asexually are known as conidia (gonidia). Each conidium on germinating gives birth to a new Mucor. The conidia while in the sporangium are separate fi'om each other, the spaces between them being occupied by a thin protoplasmic material. The sporangium now dehisces, being easily ruptured, and the conidia are dispersed ; the greater part of the sporangium wall disappears, but a small collar frequently adheres to the conidiophore. Germination. — Each conidium. is ellipsoidal in shape, has a thin fungus-cellulose coat which en- closes a cavity containing protoplasm and one or two nuclei. (1) The conidium sioells to a tenfold size, becomes globular, and contains cell sap in the form of a large central vacuole. (2) Several tubes are quickly developed, tliese grow rapidly and produce the mycelium. The successive systems diminish in size. In this stage the mycelium is unicellular ; nuclei, protoplasm and vacuoles abound. When it has covered an area of a few inches, growth ceases. (3) The protoplasyn becomes more granular and darker, and collects towards the middle of the mycelium. (4) The conidiophores are erected out of the fluid as thick unicellular filaments ; while this is going on the mycelium developes septa. (5) The conidiophore at its free end swells into a head, which is cj^uickly supplied by the dense protoplasm from the mycelium, the protoplasm being replaced by cell sap. (6) The wall of the columella is developed. (7) The conidia are developed by free cell formation. (8) The conidiophore rapidly elongates. (9) Dehiscence takes place and the spores are dispersed, which in their turn germinate. The time occupied from germination to maturity is about three days. In Ftloholus, another of the Mucorini, the sporan- gium remains intact, but when ripe becomes detached at its base, and together with the conidia is thrown some distance by its elasticity. SEXUAL EEPEODUCTION. Mucor is also propagated sexually in the following wav : — (1) Two filaments of the mycelium each put out in the direction of the other a cylindrical protu- berance resembling the filament itself. (2) These two protuberances become closely ad- pressed to one another by their ends, and grow into a club-shaped body in which a quantity of protoplasm collects. (3) Each of the club-shaped ends is cut off by a septum of cellulose, in this way the two con- jugating cells are formed. (4) The separating wall disappears, and the con- tents of both cells mingle, the result being the formation of a Tiijgospore, which is the repro- ductive organ. (5) The zygospore rapidly rounds off and enlarges considerably : the two attached mycelial threads grow large and form Suspensors. (6) The wall of the zygospore becomes considerably thickened ; the outer portions become dark, cuticularised, and often spiny, the inner re- maining a colorless layer of pure cellulose. The outer coat is called the exospore and the inner the endospore. 8 Germination ot a Zygospore. — This takes place after a period of rest — about six weeks — the inner cellulose wall produces a single hypha, the outer cuticularised wall being ruptured to allow its exit. The hypha bears a sporangium which behaves in all ways exactly the same as that borne by the ordinary mycelium. Q) fk^szO) <4)CeJ(^r^Ke) 9 Oi^clei? 3.— JLsco]39.ycetes. Type.-EUROTIUM REPENS. A fungus found on decaying or dead organic bodies, and especially abundant on preserved fruit. It makes its appearance as a delicate flocculent white mycelium overspreading the surface, from which the upright conidiophores soon rise in large numbers. ASEXUAL EEPRODUCTION. The conidiophores swell in the upper part into a globular form, and on the upper half of the globe there arise a number of peg- shaped projections densely crowded and arranged radially, so that finally the head of the receptacle is covered by a thick layer of them. These are known as Sterigmata, each of which produces a long chain of gieenish conidia by abstriction. This differs from the ordinary process of cell division only in the marked constriction of the cell in the plane of division. These conidia are sometimes called Stylospores. When ripe they drop off and germinate by putting out a filament from the endospore. SEXUAL EEPEODUCTION. During the foimation of conidia the sexual organs appear on the mycelium. The female organ, the 10 ascogonium, is a corkscrew-like end of a branch of the mycelium, the coils of which gradually become closer, and when actually in contact they form a hollow spiral. Duiing this process there are as many septa formed as there are turns of the spiral. From the lowest coil of the ascogonium two slender branches now shoot out at opposite points, and grow upwards on the outside of the spiral {helix) one of these develops more quickly than the other, reaches the uppermost coil, and becomes closely attached to it by its apex. 'J.^his branch is the polUnodium. Conjugation takes place between its apex and that of the ascogonium, the cell walls being absorbed at the point of contact, the protoplasmic contents of the two cells commingle. Soon afterwards new filaments sprout out from the lower part of the pollinodiam and ascogonium, cling closely to the spiral and finally envelop it. From these filaments a layer of polygonal cells is formed by numerous transverse divisions. The cells of the enveloping layer grow inwards as jDapillfe, which become septate. The enveloping layer increases in size, the cavity between it and the ascogonium also enlarges, the coils of the ascogonium loosen. The whole space becomes filled up by the papillae, which become 11 divided bj septa, and so form a mass of pseudo- parenchyma. A large number of septa arise in the ascogonium, and soon there shoot from its cells numerous branches, which penetrate on all sides between the colls of the pseudo-parenchyma, become septate and ramify. Their last ramifications are the Asci, which therefore owe their origin to the fertilized asco- gonium. All this time the penthecium, {i.e., the tissues developed as the result of fertilization) has been increasing in size. During the development of the Asci, the pseudo- parenchyma becomes looser, its cells round them- selves off, become capable of swelling, lose their fatty contents and disappear, their place being taken by the Asci. The outside enveloping layer from which the pseudo- parenchyma is derived keeps pace in growth aud becomes covered with a sulphur-yellow coating, which attains a considerable thickness and consists probably of a resinous or fatty substance. Finally these ceils also collapse and dry up ; the eight-spored asci also break up, till finally the perithecium consists only of the brittle yellow coating and the mass of spores enclosed by it, which are set free by gentle pressure. In a similar manner to the perithecium the mycelium also becomes covered by a coating, in this 12 case of a chestnut colour, on whicli the perithecia are now individually visible to the naked eye as yellow granules. The ripe spores have the form of bi- convex lenses ; when germinating the endospore, which puts out the germinating filament, swells up violently and splits the exospore into two halves. The mycelium which proceeds from the Ascospores produces, like that which arises from the conidia, at first Conidiophores, and afterwards Perithecia. (^^'^(S'^^K^^K^ 13 Type.-MUSHROOM. AGARICUS CAMPESTRIS. The common Mushroom consists of : — (1) The mycelium. (2) Th.e fructifications. (1) The Mycelium is composed of septated hyplise, containing many small nuclei, and abundant protoplasm. It vegetates on decaying animal or vegetable matter. From the mycelium spring a number of fructifications. (2; Development of the Fructification. — This consists at first of a solid, pear-shaped body composed of young hyphse, all similar to one another. At an early stage an annular air- cavity is left just beneath the apex, the upper wall of which becomes the under side of the inleu8^ and from this radial hymenial lamell(B grow down, filling up the cavities. The tissue below the cavity elongates into a stalk, while the hj^phse forming the margins of the pileus constantly increase. The hyphse which lie beneath the air-cavity become stretched and se^^arate from the stem from below upwards and so form a membrane. This runs from the upper part of the stalk to the margins of the pileus, into which their hyphse are continued. As 14 the pileus goes on extending horizontally, this membrane becomes detached from the pileus, and hangs down from the stem like a ruffle. This is called the Annulus. STEUCTURE OF THE STALK. The hyphse are arranged parallel to each other generally, but single ones run obliquely to the others. The parallel hyphse are branched, each branch usually arising just under a septum. The external ones are narrow and close together. In the middle the arrangement is irregular, and air fills the inter- spaces. In the latest stages vacuoles and crystals of Calcium Oxalate appear. In cross section it will have a parenchymatous appearance. Pits are fre- quently seen in the cross walls, one usually occupying the middle. REPEODUCTION. The pileus bears on its underside a number of lamelliform projections. A section cut at right angles to the course of the lamella) will exhibit a comb-like appearance. Highly magnified each tooth of the comb shows the following structure : — (1) A number of septated hyphae called the Trama. They diverge from the centre to the right, and form: — (2) The suh-hymenial layer. From the sub-hymen- ial layer arise short, club-shaped hyphse, densely crowded, and at right angles to the 15 surface of the lamellae. These form : — (3) The Hymenium. Many of these club-shaped sacs remain sterile. These are caRed Para- 2)hyses^ others produce the spores, and these are called Basidia. Each basidium produces in this species only two, in other Basidiomycetes usually four spores. The basidium puts out first of all as many slender branches as there are spores to be formed. These branches are the Sterigmata. Each sterigma swells at the end : the little swelling is cut off by a wall, and becomes a spore. In this species the spore remains smooth. "When ripe it falls off from its sterigma. The spore is ellipsoidal in shape, and is known as a Basidiospore. The wall of each spore is thick in proportion to its size, it contains abundant protoplasm, many small nuclei and vacuoles even before it is septated from the sterigma. When germinating it produces several tubes, which give rise to the mycelium, this in its turn produces the pear-shaped solid masses of hyphse which ultimately become the fruits. A development of sexual organs, by means of which the formation of the fruit could take place, has not yet been observed. 16 Class. — LICHENS. Type.-COLLEMA PULPOSUM. " Lichens are true fungi belonging to the Ascomy- eetes ; they are distinguished by a peculiar parasitism. Their hosts are Algce which grow in damp places, but not actually in water. Lichens are not found in any other form but as parasites on Algse. The Algae when combined with the Fungus, are called Gouidia, and these Algse are known in a free condition without the fungus. The gonidia of Collema has been identi- fied with the alga Nostoc. The algee grow as stains and incrustations on damp ground, the bark of trees, and stones. The separate cells and groups of cells become so involved by the tissue of the fungus that they at last are only interspersed here and there in the dense hyphal tissue of the fungus." 1. GENERAL CHAEACTERS. Collema grows on moist earth and rocks. Its thallus (the whole plant — so called because it shows no differentiation into root, stem, and leaf) may be aU but ground to a powder without destroying its vitality. When saturated with water it becomes slimy and gelatinous, and is therefore known as a Gelathious Liclien. Farmelia, another lichen, becomes leathery when saturated witli water, and this, therefore, is placed in the non-gelatinous class. Collema is again classed as a Foliaceous Lichen, because its thallus is green and leaf-like in appearance. 2. STRUCTURE. In section Collema shows an epidermis or cortical rind, forming a sort of pseudo-parenchyma. This rind consists of a number of septated hyphcB, which do not differ in any particular from the hyphae of the fungi already discussed. It is the cut ends of these elements which are seen in section. The interior consists of a colorless jelly, in which lie chains of gonidia and numerous hyphm. The gonidia and hyphee are about equally mingled, and the thallus is said to exhibit a homoiomerous structure. (a) Gonidia- The wall of each cell is composed of normal cellulose, lying next to this is a band of protoplasm containing chlorophyll grains, and the centre is occupied by either a colorless or a blue vacuole. A nucleus is always present embedded in the protoplasm. These cells — gonidia— are arranged in bead-like rows. One or more cells in each chain is larger than its neighbours, and is colourless. (b) The Jelly is now universally believed to be the outer gelatinous walls of the gonidia. 18 (c) The Hyphae are elongated, greatly-interlaced, tube-like structures. Their walls are enormously thick when compared with the size of the cavities. . 3. PHYSIOLOGY. (a) Respiration. Oxygen is absorbed, and carbon di-oxide liberated as in the higher plants. (b) Assimilation. The gonidia, as they contain chlorophyll, decompose Carbon di-oxide and water, and build up starch, at the same time liberating Oxygen. This can only go on in the presence of sunlight. The hyph?e fit closely to the gonidia, and carry to them the crude sap which contains in solution Nitrate of Potassium, Sulphates of Calcium and Magnesium, and Chloride of Iron. These are all obtained from the soil or rock on which the lichen is flourishing. In return the hyphee receive a share of the organic material elaborated by the gonidia. Gonidia and Hyphae are thus closely associated and are dependent on each other ; the gonidia receive from the hyhpae the crude material, the hyphae receive from the gonidia elaborated material. This mutual give and take is called Symbiosis, and is nowhere else exemplified in the vegetable kingdom. 4. MODE OF GEOWTH. The mode of growth, external structure, and branching are all determined by the gonidia. The details are as follow : — 1. The branch increases at the apex by the trans- verse division of a gonidium which forms the apical cell of the branch and by the longitudi- nal growth of the hyphee. 2. The cells produced from the apical gonidium divide parallel to the long axis of the branch. 3. New divisions take place in different directions, and thus groups of gonidia arise at some dis- tance below the apex. 4. A few hyphse follow the longitudinal growth and these grow within the gelatinous en- velopes which are evidently derived from the gonidia. 5. A.t a considerable distance behind the apex new hjrphae put forth lateral branches which penetrate between the single or grouped gonidia, and this increases the branch in thickness. 6. When a lateral branch is about to be formed one of the exterior gonidia lengthens in a direction at right angles to the axis of the parent branch. This becomes the apical cell of the lateral branch, and produces new cells by transverse division. 7. Branches of the adjacent hyphae turn in the same direction and behave in relation to the 20 new apical cell, in the same way as those of the parent branch. 8. The thallus increases in thickness by the branching of the hyphae and the multiplication of the gonidia. EEPRODUCTION. 1. Sexual {not universally accepted). Flash-shaped depressions occur in the thallus called Spermogonia, in these are produced rod-like cells called Spermatia, by the process of abstriction. Each of these cells is regarded as a male reproduc- tive organ. The female organs are coiled hyphee, which form spirals somewhere in the thallus, and then the ends run straight to the surface, and project slightly above. A single coiled hypha is an ascogonium. Many ascogc»nia occur in one thallus. The male cells are brought by water, and come in contact with +he straight part of the female organ. The walls between become disorganised and the con- tents of the male cell [spermatium) are conducted to the ascogonium. Conjugation is thus effected, and the result of this conjugation is the formation of special receptacles called Apothecia. Note that the whole of the Sexual process is entirely concerned with the HyphcB. *^' III — ~ 22 -— — ' 3. Formation of the Lichen. Before the dissemination of the spores some of the Gonidia crawl out of the parent plant and settle themselves at some Httle distance off. They produce the jelly and the large colorless cells, and so are ready to become the hosts of the fungus. The spoies falling in their neighbourhood germin- ate by putting out as a rule two filaments (hyphse) from the endospore. They come in contact with the jelly of the gonidia and grow and ramily in all directions, until the little group of gonidial cells is entirely invested by their threads (hyphae). A new lichen is thus formed ; the young hyphse take up the necessary food from the substratum, and convey it to the gonidia, which assimilate it ; the gonidia use part of it for the growth and multiplication of their own cells, and give up the rest to the hyphse. The thallus begins at once to produce the apothecia, which in their turn produce the spores ; some of the gonidia wriggle out and away to form a new host for the germinating spores. Facts in support of the Algo-Lichen theory above discussed. 1. If the green element be isolated from the fungus and cultivated, it gives a life history identical with some known alga. The alga of Collema is Nostoc. 23 2. "While the gonidia are flourishing they never show even a tendency to produce the colorless liyphse. 3. When the spores germinate and the h3rph8e are not allowed to come in contact with an appropriate Alga they soon die and during their short span of life they remain colorless. GAgy^"^ «4i^ oj^.cJ c/^ r> 25 volume to the amount of CO^ decomposed. This process is called Assimilation, and may be repre- sented thus:— 6 CO2 + 5 H2O = Ce Hio O5 -f 6 O^. The Chlorophyll grains are larger than the ordin- ary grains of protoplasm, and as a rule lie next to the cell wall. The nucleus occupies the centre. 'I he changes to the active condition are as follows : — (1) The protoplasm withdraws itself from the wall, except at two points. (2) The protoplasm at these points protrudes through the wall as long threads. (3) The cell wall becomes disorganised, and it now swims about as a naked cell, called a Zoospore, in which a red spot is clearly visible. This is known as the ** Eye-spot." Note. — One cell may produce as many as eight zoospores, thus : (1) The protoplasm splits into as many parts as there are zoospores to be formed. (2) Each mass develops two cilia, which protrude through the wall. (3) The mother cell is disorganised, and the zoospores are liberated. Changes to the encysted condition. (1) It loses its cilia. (2) It clothes itself with a cell wall, and becomes quiescent. 26 EEPRODUCTION. Brought about by ordinary cell division : —• (1) The nucleus divides into two. (2) A cell wall is developed in the plane of the division. Each of these cells can repeat the process. (3) The daughter cells round themselves q&. They may remain in union with each other for some time, but finally separate. In all probability the Protococcus is only a form of some higher Alga. Frotococcus nivalis is ''red snow" — resembles P. pluvialis in all respects except in its colouring matter. P. Atlanticus, another species, imparts a red colour to the waters of the Atlantic in some places, and it is probably better to distinguish this as well as P. nivalis as Rcematococci. 6<^ GY^) (Sr^ e) 6Y^ Ke) 27 Type-SPIROGYRA NITIDA. Spirogyra is a freshwater alga found particularly in ponds and springs, and may be recognised by its bright green or yellowish colour, as well as by the delicacy of its filaments. Each plant consists of a single, cylindrical, unbranched, thread of cells. Each cell wall is lined by a delicate, colorless, peripheral layer of protoplasm, which becomes clearly visible when the cell is treated with some water- withdrawing medium (solution of common salt or glycerine). The chlorophyll takes the form of closely-wound spiral hands having a finely undulating outline, lying next to the protoplasm ; embedded in the band are the amylum bodies, sometimes known as pyrenoids. These are dense globular colourless grains, each of which contains a protem crystal, and is bounded by a hollow globe of small starch grains. A nucleus occupies the centre of each cell, and in some species exhibits the form of a bi-convex lens. In the centre lies a nucleolus ; sometimes as many as three nucleoli are present. The nucleus is surrounded by a very thin layer of protoplasm, from which delicate protoplasmic threads 28 run out towards tlie peripheral protoplasm ; these threads fork repeatedly and suspend the nucleus in the cell sap. The protoplasm also contains numerous drops of oil. EEPRODUCTION. Two threads lie alongside of each other, the cells of each put out short blunt projections which come into contact, the absorption of the walls at the point of contact forms a narrow canal ; since a number of cells usually conjugate at the same time, the whole forms a ladder-like structure, in which the rungs are represented by the canals. After the formation of the conjugating canal the contents of the male cell round themselves off and withdraw entirely from the wall. They then pass into the canal and enter the female cell, which has rounded off (or is in the act of rounding off) its con- tents, both masses come into contact, and after a few minutes coalesce, i.e., the protoplasm fuses, the chlorophyll bands join together, and the two nuclei unite into a single one. The result of this fusion is the formation of a globular or ovoid body, which first contracts and then acquires a thick cell wall. The whole still lies within the much larger mother cell. After a lapse of about twenty-four hours the chlorophyll band is pressed outwards, and the nucleus assumes a central position. 29 GERMINATION. This takes place after a period of rest, so tins zygospore is termed a resting spore. Usually in the spring following its formation it escapes from the parent cell by the decay of the mother filament, or it may germinate while still within it. The innermost layer of the cell wall bursts through the outer ones, and develops into a filament like the parent plant. Gt^Grt)(s r4j^e)G^^}Ce) 30 Type-COMMON BLADDER WRACK. FUCUS VESICULOSUS. This Alga may be olive-green or brownish, in ccilour ; it is flat, leaf-like, cartilaginous in texture, traversed by a midrib which projects on both sides, and bears bladder-like swellings in pairs (one on either side of the midrib) as well as singly at the base of the bifurcations ; it is attached to stones by a branched attachment disc. The whole plant is called a Thallus because there is no differentiation into root, stem, and leaf. The branches of the Thallus are all in one plane, and as a rule the branch- ing is dichotomous, i.e., the apex ceases to grow in the original direction, and its continuation is in two new directions ; the two newly -formed branches are termed bifurcations, and the member which j)roduces them the hase of the bifurcation. Every base can only bifurcate once, but every branch may become the base of a new bifurcation. Dichotomous branch- ing is common to all the Algse, but in some Fucacese the branching is si/mpodial. This is the case when one branch develops more strongly than the other, and the weak one then appears to be laterally developed ; the bases of the successive bifurcations 31 appear to constitute an axis (which is called a pseud- axis or sympodium) on which the weaker branches appear as lateral branches, the successive bifurca- tions are alternately right and left, and so form a scorpioid dichotomy. The growth is brought about by a group of cells at the apex, called primary meristem, this lies in a depression, and is not differen- tiated. (In other cryptogams it is usually brought about by a single cell). GENERAL ANATOMY. The tissue consists at the surface of small cells, next to this it is laxer, and the midrib consists of thickened elongated cells. The cell wall consists of two distinct layers, an inner thin firm one, and an outer gelatinous one (capable of swelling greatly in water) which fills up the interstices of the cells, and has the appearance of a structureless substance ; this is the cause of the slimy character which the FucacecB assume after lying in fresh water. The granular contents appear to be mostly brown, but contain chlorophyll which is concealed by other colouring matters. The colour bodies are known as Plmophyll grains, and vvhen treated with alcohol yield an olive- green extract ; this extract when shaken up with, double its volume of Benzine, and allowed to settle, produces an upper green layer containing the chloropliyll, while th« lower alcoholic layer is yellow, and contains Phycoxantheine. 32 MINUTE STRUCTURE. (1) Epidermoid layer. The cells are oblong in surface view, and rectangular in section ; the cavities are closely filled with protoplasm and phseophyll grains. * (2) The Cortex is several cells in thickness and contains wide cavities filled with phseophyll grains, the cells are connected by pits — these are thin places in the cell- wall. The innermost layer of the cortex is the thickening layer (analogous with cambium in Phanerogams). (3) The Midrib consists of elongated cells connected together into threads which run parallel to each other and to the long axis ; the transverse walls are interrupted in a sieve-like manner, the threads are separated laterally by the jelly, which is bridged over by canals ; the long walls are in- terrupted by broad pits. (4) The Wings. The midrib is surrounded by a loose network of irregularly dispersed cells, and this passes over laterally into the packing tissue of the wings. This tissue is made up of irregular, thread-like cells similar to those of the midrib, it is poor in pheeophyll grains, but is rich in oil globules. A starch reaction is nowhere found. The epidermoid and cortical tissues are assimila- tive, the packing tissue and midrib conductive. (5) The Bladders are swellings which in a young state are filled with threads similar to those found 33 in th.e wings of the thallus ; scattered in tKe jelly belonging to these threads are bubbles of gas, which tear the loose tissue, and form the chambers of the bladders. Old bladders are hollow and filled with air and serve as swimming bladders, the outside walls are thick, being formed by successive divisions of the epiderm oid layer. (6) The Stem. The tballus in its oldest part is stem-like, and developed from the midrib, the wings of which have gradually died off. The innermost layer of the cortex (the thickening layer) begins its activity at an early stage ; at a little distance below the apex, tube-like prolong- ations are developed, which grow downwards into the jelly separating the threads ; these divide by cross-walls and branch from time to time, these thickening threads rarely pass into the wings. In cross-section the two kinds of elements can be distinguished : — (i) Scattered cells with brownish contents (primary tissue.) (ii) Numerous closely-packed cells with narrow cavities and greenish contents (secondary tissue). While this has been going on the wings have died off, the outer layer of the midrib has become brown and dead and cast off, the second layer becomes 34 active, divides up by radial walls and soon closes round. Fucacece yield Acetic Acid when fermented at a temperature of from 90 to 96 degrees Falirenheit, The epidermoid is in positive and the outer layer of the cortex in negative tension, that is, the outer layers are compressed by the inner layers, and the latter stretched by the outer. EEPEODUCTION. The Anther idia (male) and Oogonia (female) are formed in spherical hollows — conceptacles — which make their appearance in large numbers at the ends of the branches. Each conceptacle communicates by a narrow channel — the osteole — with the sea water. The layer of cells which clothes the hollow is a continuation of the external epidermal layer of the Thallus and since the filaments which produce the Antheridia and Oogonia sprout from it, the latter are morphologically trichomes (any outgrowth from the epidermis, e.g., hairs, is called a trichome.) Some species are moncecious, i.e., both kinds of sexual organs are developed in the same conceptacle, as in Fucus platycarpus (this species is further charac- terised by always being devoid of air-bladders) ; others are dioecious, i.e., the conceptacles of one plant containing only oogonia, those of another only antheridia, as in F. vesiculosus. A number of hairs which grow in the conceptacles among the sexual 35 organs are long, slender, articulated, unbranched, and project in F. platy carpus out of tlie mouth of the conceptacle in the form of tufts — these help in the absorption of nutrient materials. Sterile conceptacles are often found — no doubt being produced to further aid in the absorption of nutrient matter from the sea water. The Antheridia are produced as lateral ramifica- tions of branched hairs. Each antheridium consists of a thin-walled oval cell, the contents of which go to form numerous small antherozoids ; these are pointed at one end, and each is furnished with two unequal motile cilia ; the short one is attached to the pointed or anterior end, and directed forwards ; the longer one is attached laterally and directed back- wards. The antherozoid consists of nuclear sub- stance, and always shows one reddish-brown spot — due to the presence of one and very occasionally two colour bodies. It is at this spot that the lateral cilium is attached. The nuclear substance is sur- rounded by a thin layer of protoplasm — Kinuplasm. The whole of the contents of the antheridium is not used up, a little protoplasm is left. The Oo^onia. The formation of an oogonium begins with a papillose swelling of a parietal cell of the conceptacle ; the papilla is separated o:ff by a septum, and divides as it grows in length into two cells, a lower, the pedicel cell, and an upper, which forms the oogonium. This swells up into a spherical 36 or ellipsoidal form and becomes filled with dark fine- grained protoplasm; it contains a nucleus which, by successive bi-partition becomes eight nuclei. Tha protoplasm separates into eight portions with a nucleus and a brown fleck in the middle of each (due to the aggregation of colour bodies). These com- pletely fill up the cavity and pressing one against another, become polygonal. Each mass is an oosphere or female reproductive organ. (It is analogous with the ovum in higher plants). The wall of the oogonium consists of two layers, the outer one splits, and the inner one protrudes in the form of a sac, which becomes distended by absorption of water ; in this enlarged sac the oospheres become globular. The inner membrane now splits and the oospheres are liberated as naked balls of protoplasm, each of which has a central nucleus and its colour bodies equally diffused. At about the same time the Antherozoids are liber- ated by rupture of the antheridium, they swarm in large numbers round the oospheres, become attached to them by their anterior cilia — if their number is sufficiently great their movement is so energetic that they impart to the oospheres a rotatory motion which may last for half-an-hour. This phenomenon is nowhere else exhibited in the vegetable kingdom, though it is known in several genera in the animal kingdom. Some of the antherozoids mingle their substance with that of the oosphere, whose motion 37 ceases, and fertilization is effected. A sliort time after, a cell wall is secreted. This cell {oospore) fixes itself to some body, and without any period of rest begins to germinate. It forms first of all a transverse wall and begins to lengthen at the same time. Numerous other cell divisions follow and the mass of tissue thus formed puts out from the part on which it rests a root-like organ of attachment. The thick free end forms the growing apex. eti^e,>{K3i^Ki) 38 Class.— MUSCINBJE. Sub-Class. -HEPATIC^^. 0]?de]?.—lV[£t]?cli. £1.1:1 tiese. Type.-A LIVERWORT. MARCHANTIA POLYMORPHA. •^ GENERAL MORPHOLOGY. Marchantia has a tougli, leathery, thalloid stem, extended flat upon the ground, it is ribbon-like, dichotomously branched, and green. Along the centre of each shoot projects on the ventral (under) surface a ruidrib. The existence of simple, scale-like leaves can be detected with the aid of a microscope. There may be present three forms of scales : — (1) Marginal scales which have become brown. (2) Median scales, which lie in the middle line, and are usually purple. (3) Laminar scales, which lie on either side of the middle line. The ucder side of the thallus also produces fine rhizoids^ which are not true roots. 39 Tlie upper surface of the thallus is interrupted by cup-like depressions called Gemmm cups. With the aid of a lens the upper surface is seen to be divided into small, diamond-shaped areas. The limits of the areas are dark-green, the areas themselves being greyish. In the middle of each area is a dot-like opening surrounded by foiu' narrow cells containing no chlorophyll and curved in the form of a crescent. GENEEAL ANATOMY. In surface view the cells of the epidermis appear to be polygonal. The under surface shows no divi- sion into areas. A cross- section of the thallus beginning at the dorsal (upper) surface, shows the following structure : — 1. Epidermis. This is very distinctly differentiated, and is inter- rupted by large stomata of a peculiar form. The cells are generally oblong or polygonal, and contain numerous small chlorophyll grains. The Stomata. Each stomata stands in the centre of a rhombic plate which overarches a large air-cavity, and which is formed by the upper cells becoming detached from those underneath. The stoma is formed by the simple separation from one another of four or more epidermal cells which afterwards 40 divide by walls parallel to the surface of the thallus. For this reason the opening is sur- rounded with from four to eight tiers of cells. The opening is narrowed at its upper and under surfaces, and therefore shows a barrel-shaped form. 2. Intercellular Spaces. Under each stoma is found a large, intercellu- lar space, into which project from below threads of cells (two or three cells long) occa- sionally branched. These cells are especially rich in chlorophyll, and they arise fiom the flat- tened cell layer next below which is poor in chlorophyll. The walls bounding the air-chamber laterally are constructed of loosely-combined cells, which also contain chlorophyll. 3. Cellular Tissue. The tissue next under this consists of broader cells, which have reticulately thickened walls. They are almost free from chlorophyll and have no interstices. 4. Ventral Cortical Layer. Approaching the -ventral surface the last two layers are flat and narrow, and contain chloro- phyll and form the so-called ventral cortical layer. 5, Epidermis. The epidermis of the under surface is much 41 poorer in cliloropliyll, and the cells are more elongated. The Rhizoids, i.e., Filaments whicL. attach the plant to the substratum, and absorb water together with the necessary food material, proceed from the ventral surface, and are of two kinds. (1) Thin-walled ones, with peg-like projections in the interior. (2) Thick- walled ones without peg-like projections. Those with the peg-like projections in their inte- rior lie close to the frond, and follow the midrib in bundles and are covered by the scales. They serve perhaps the purpose of stiffening the thallus. Those without the peg-like projections turn off from the thallus at once and enter the substratum. At their apex they are sinuately lobed, at their base purplish. The Scales are the leaves which are simple plates one cell in thickness. The median cells are living, but the outer edges become brown and die off. The projecting midrib consists of elongated thick- ened cells which contain no chlorophyll. The Thallus grows by a group of apical cells. Throughout the entire tissue are single cells, which are distinguished by a highly refractive, irregularly- outlined, grape-like body, which in the youngest shoots are slightly brownish, and in the older ones dark brown. These are oil hodifis^ which are charac- teristic of Liverworts. 42 In Marchantia are also found large cells with highly refractive contents, which on examination proves to be mucilage. EEPEODUCTION. Ye^etative. Multiplies by ^ ^ "f • Moss Plants produce feexual Organs. ) Sexual Organs produce Sporogoniuua. \ Sporophyte Sporogonium produces Spores. | Generation. The alternation of generations in the MuscinecB is the converse to that exhibited in the Vascular Cryptogams. The Sporophyte is parasitic upon the Oophyte Generation. G^V^(^^%^y:^K^ 66 Class.— LYCOPODIN^. "^^ Type.-SELAGINELLA MARTENSII. s MOEPHOLOGY. Habit. — Creeping stems, dichotomo'n.sly branclied — brandies all in one plane — bearing two kinds of leaves, large and small. These are ligulate. The large ones are inserted on the ventral surface, and the small ones on the dorsal. One large and one small leaf make a pair. The arrangement is decussate. Besides the leafy branches, leafless ones — rhizophores — are produced where the stem forks. These grow downwards, and produce at their apices tufts of true roots provided with caps. Growth. Grows by means of a four- sided apical cell, which cuts off segments parallel to each of the three sides which are imbedded in the sur- rounding tissue. ANATOMY. Stem. Epidermis. Thickened outer cortex — thin inner cortex — no intercellular spaces — (interrupted by small leaf trace bundles) and the central cylinder consists of either one or three vascular bundles. 57 Bundle. 1. general ghaeacters. Centric, i.e., the tissues are arranged in concen- tric zones. Closed, i.e., no generating tissue called cambium is present. Cauline, i.e., each bundle is found to terminate in the stem, and does not enter a leaf. 2. TISSTJES. (a) Wood or Xylem, which shows two protoxylem groups, and two sets of elements. These are traclieides and parenchyma. Each tracheide consists of an elongated, thick- walled empty cell, whose great function is to carry water. The traclieides are marked by bordered pits. The parenchyma consists of smaller cells, re- tains its contents, and stores up starch. (b) Bast or Phloem. This surrounds the wood, and consists also of two sets of elements. These are Sieve Tules (or Bast Vessels) and 'parenchyma. The Sieve Tubes are elongated, contain protoplasm and various albuminoids, but no nucleus. They are characterised by perforations on their inclined and radial walls, through which the contents stream. Their great function is to conduct the albuminous food material. The Parenchyma is thin- wallod, each cell is nucleated and stores up albuminous food material. 58 The Pericycle is one cell in thickness, forms a sheath, round the phloem, and stores up starch. The Endodermis, which in Ferns and the higher plants consists of a continuous ring of cells, is here represented by a large air-space, tra- versed by bridges of tissue called Traheculce. Leaves. Small — sessile — thin. Epidermis. Cuticularised, and contains chloro- phyll. Stomata. Middle of under surface. Mesophyll. Not differentiated. Bundle. One — same structure as stem bundle. Root. General structure same as stem except that the skin being absorptive, is known as the pilifery, instead of epidermis. Branching mostly exogenous — segments cut o:ff by the apical cell form the lateral roots. Root Growth. An apical cell. Free upper sur- face cuts off the cap cells. The other segments cut off as in the stem. EEPEODUCTION. The male and female reproductive organs are produced on fertile branches. The fertile leaves form a quadrangular spike, the leaves are uniform in size and usually somewhat of a different form from the barren ones. 59 The S^porangia are of a considerable size in pro- portion to the leaf, and are borne on short, thick stalks. Each fertile leaf bears a single sporangium, which always lies below the ligule, either on the leaf itself or on the stem. Each sporangium is a capsule. Capsules containing four (2-8) large spores (female) are called rnegasporangia or macrosporangia. Capsules containing an indefinite number of small spores (male) are called microsporangia. The micro- sporangia are borne on one side of the branch, and the megasporangia on the other aide, or the micro- sporangia above and the megasporangia below. DEVELOPMENT. The early stages are the same in both cases. I. Microsporangia. (1) A group of superficial cells in the axil of the Hgule becomes active, and gives rise to a small protuberance. By repeated division a mass of tissue is formed which differentiates into an outer layer and an internal group, one of which, the hypodermal cell in the axial row, becomes the archesporiutn, and the lower ones the stalk. (2) The archesporium cuts off cells which go to form the tapetum on the free side, and the cells of the ground tissue form it towards the base. (3) After the development of the tapetum, the archesporium divides up rapidly, and produces 60 a mass of spore mother cells. While this has been going on the outer wall divides up by- tangential walls, and so the wall of the sporan- gium is now two cells in thickness. (4) The mother cells round themselves off and become isolated from each other. Each mother cell divides up into four daughter cells, each of which is tetrahedrally shaped : they retain their relative position until mature. An im- mense number of these small spores is thus produced. The tapetum persists until the spores are ripe (while in ferns it is absorbed during the formation of the spores). The fol- lowing changes, called Germination^ now take place while the spores are still within the Sporangium: — (a) At one end of the spore a small cell is cut oif by a very fii'm wall. This cell has no function to perform, and is called the Vegetative Cell,, and may be considered as a rudimentary prothallium. (b) Successive division now takes place in the larger part of the spore— the whole of this tissue is regarded as the Anther idium,, and the central tissue becomes the Antherozoid [spermatozoid) Mother Cells. (c) Each mother cell contains a nucleus and protoplasm. The nucleus grows at the ex- pense of the protoplasm, and forms a spiral 61 body, which, is orginally curved round the central vacuole. In the meantime, the proto- plasm which is left, becomes differentiated into two delicate fibrils, which attach them- selves to the spiral nucleus at one end. The vacuole, not unfrequently, as it is sur- rounded by a delicate layer of protoplasm, remains attached to the posterior end of the Antherozoid. (d) The sporangium bursts, and the spores fall to the ground. From the commencement of germination to the maturity of the anthero- zoids there is an interval of about three weeks. II. Megasporangia. Stages 1, 2, and 3 same as Microsporangia. (4) One mother cell grows more strongly than the rest ; it divides, and gives birth to four mega- spores — again tetrahedrally shaped. The megaspore is surrounded by a cuticularised wall which is difficult to cut. All the other mother cells remain undivided — their ultimate fate is to be absorbed, though they exist in some species for a considerable time. Germin- ation begins to take place while the megaspore is still IN THE Sporangium. (a) The protoplasm lying towards the corner divides up and forms a delicate plate-like cellular tissue, which afterwards produces 62 the archegonia, and is therefore the true prothallium. Usually at this period the megasporangium bursts, and the spores fall to the ground, (b) A few weeks after dissemination, free cell formation begins in the remainder of the spore cavity, and the whole space is filled up by a large-celled tissue which is called Endosperm. The megaspores now contain both a prothallium and an endosperm. DEVELOPMENT OF AECHEOONIA. The archegonia are produced from the prothallium thus : — (1) A superficial cell divides parallel to the surface. (2) The upper of the two cells divides into four cells by two walls at right angles to each other. (3) Each of these divides into two by an oblique wall. In this way the neck is formed, consist- ing of four rows, each two cells in thickness. (4) The lower of the first two cells sends out a narrow prolongation between the neck cells ; this becomes the canal cell of the neck — this neck canal cell forces the neck cells apart. (5) The lower swollen portion cuts off a small cell which is called the ventral canal cell and the inferior large one the ovum or oosphere. (6) The two canal cells now become mucilaginous, and the archegonium is ready for fertilization. 63 All these changes have gone on in the spore, the early ones while the spore was in the sporangium, and the later ones after the dissemination of the spores. The outer cuticularised wall bursts soon after the archegonia begin to appear, the prothallium is liberated and slightly protrudes ; the three con- vergent edges burst lengthwise and form a three- rayed fissure. At the apex the first archegonium is in process of development. FEETILIZATION. This mast take place in water. The walls of the Antherozoid mother cells become disorganised, and the antherozoids are set free. They show active movement and swim away by means of their cilia. Their movement after liberation lasts from thirty to forty- five minutes. A drop of mucilage exudes from the archegonium — the antherozoids swim about aim- lessly till they come within microscopic distance of an archegonium. They approach the opening, become entangled in the mucilage, and screw and wriggle down the canal until they reach the ovum. One antherozoid fuses with the nucleus of the ovum, and fertihzation is effected. Changes after Fertilization. (1) The ovum secretes a cell wall. (2) Division by a transverse wall takes place. (3) One of these cells elongates, and forms the suspensor, which gives rise to a number of 64 divisions on the side nearest the embryo — this suspensor is wanting in all other Cryptogams, but universally present in Phanerogams, and through which Selaginella consequently ap- proaches the flowering plants. (4) This elongation causes the embryo to be forced into the tissue of the endosperm, where it undergoes further development. Two cells are formed by a transverse wall, these divide by a wall at right angles to the first. Two of these cells go to form the foot, which conveys nourishment from the prothallus to the growing stem and leaf. The root is formed some time after, from one of its inner segments. The foot is a characteristic of Cryptogams. One of the remaining cpUs of the original four goes to form the stem, and the other the leaf. 6r^ G^^ (S<^^0C3 G^^ Ke) 65 Class.— FILICINE^. Oi?^■ ■■,-.fi;-.