BY L. KODWAY 5 



The group is composed of two sections cieaiiy marked 

 off from one another, mosses and hepatics. iiiere is a 

 superficial resemblance, causing both to be spoken of as 

 mosses, but the difTerence between them is great. When 

 the spore of a true moss germinates, there is first produced 

 a more or less copious development of a septate filament, 

 the protonema, which bears a superficial resemblance to a 

 filamentous alga. The moss plant appears as a bud upon 

 this. With a hepatic the protonema is slight or absent, 

 and the distinction between it and the plant body is not 

 well marked. The plant in the former group is always 

 differentiated into stem and leaf, and growth is apical from 

 a single three-sided initial cell, except in Fissidens, where 

 in the branches it is reduced to a two- sided v/edge. In hepa- 

 tics there is much greater variety of form from leafy stems 

 to flat undifferentiated plates. The tissue? are simple ; in 

 large forms there is often a simple water-conducting sys- 

 tem, but no epidermis and no stomata. In some hepatics 

 there is a peculiar air-conducting system, but of an entirely 

 different character to that of the higher plants. Except 

 in one genus, Anthoceros, the chloroplasts are small and dis- 

 coid ; in Anthoceros they are single and bell-shaped, a fea 

 ture recalling the condition in some algae. The presence 

 in this genus of pyrenoids is another feature peculiarly 

 algal. 



Propagation may be effected in either section in vari- 

 ous ways, detached portions, buds, gemmae, or even single 

 cells. This is commoner in the hepatics. Reproduction is 

 always by antheridia and archegonia, which are consider- 

 ed strictly homologous with those organs, as found in ferns. 

 The antheridia are simple flask-shaped, or rarely spherical, 

 bodies, superficial, except in few hepatics, and derived from 

 a single cell. The spermatozoids are elongated, curved, 

 and bear at the anterior end two long flagella, by means 

 of which they maintain energetic progression in wat^r. The 

 archegonia are flask-shaped, generally superficial, sunk in 

 the frond in some thalloid hepatics. At maturity the 

 archegonium contains one naked egg-cell in its venter, and 

 the disorganised substance of the canal cells oozes out from 

 the apex of the elongated neck. A spermatozoon attracted 

 by this substance enters the archegonium and fertilises the 



The embryo soon surrounds itself by a wall, and imme- 

 diately commences to develop. This new being, the sporo- 

 phyte, remains permanently attached to the parent plant, 

 sending a foot into it, through which it absorbs all or at 



