VAUCHERIACEJ3. 115 



or two principal roots, which become gradually ramified into many fine 

 rootlets; the chlorophyll contents at the beginning dense and homo- 

 geneous, and clothing the inner cell membrane, extend only to the neck 

 of the root ; the membrane is rather rigid. Upon being broken the cell 

 contents become extruded, the membrane collapses as a thick pellicle, 

 whose contents admit of being completely pressed out. The fluid 

 contents in this condition consist of finely granular plasma, tinged by 

 chlorophyll granules. Subsequently the green plasma layer becomes 

 separated from the membrane, breaks up into single equal-sized portions, 

 which become rounded off, coated with a membrane, and gradually 

 individualized as daughter-cells. At last the entire globose cell is 

 densely filled with rounded daughter-cells ; whilst, previous to this state, 

 the plant presented an intensely grass-green colour, it shows in this 

 latter state a clear or sea-green colour. Mature and immature plants 

 hence readily admit of being distinguished by the tint with the unassisted 

 eye. The membrane of the mother individual at last passes to decay ; 

 it collapses, and the daughter -cells become the germs of new indivi- 

 duals in the soil. The maturity of the individuals occurs towards 

 autumn, and accordingly the germ cells lie resting in the earth during 

 winter, and germinate in the following spring. The development of the 

 germ cells to new individuals takes place without formation of a 

 ' prothallus ' ('ohne Vorkeimbildung '). One end elongating as a root, 

 at once penetrates the earth ; the other end becomes developed as the 

 above-ground portion. The diameter of a ripe germ cell is 0'009-0'012 

 mm. The plants prefer to establish themselves on the surfaces of the 

 large clefts which are produced when the waters retreat and the ground 

 becomes gradually dried by the air." Reinsoh. Algeti Flora, p. 218. 



See also " Grevillea" Vol. iv., p. 105, since which period the Memoir by 

 Eostafinski and Woronin has appeared, and that has pretty well estab- 

 lished the complex character of reproduction in this little plant. 



FAMILY II. VAITCHEBIACE^E. 



Algae monoecious (rarely dioecious), casspitose, unicellular or 

 bicellular. Thallus with terminal vegetation, utricle- shaped, 

 elongated, more or less branched. 



Propagation either sexual, by oospores fecundated by sper- 

 matozoids, or non-sexual by zoospores. 



Sporangium terminal, formed by the globosely clavate swelling 

 of the tip of the thallus, cut off by a septum, contents dark 

 green, at length enclosing one large zoospore, densely clad with 

 vibratile cilia. 



Oogomum lateral, sessile, or borne on a more or less elongated 

 simple, or partite, pedicel ; cytioplasm at length converted into 



a large oo spore. 



Antheridiwn lateral, sessile, or cut off by a septum from the 

 upper portion of a lateral branch, in which numerous spermato- 

 zoids are generated, which at length become free. Spermatozoids 

 oblong, furnished with two unequal cilia (except in one 

 species). 



