Ill THE JUNGERMANNIALES 107 



quadrants, a series of curved walls intersecting the inner walls 

 of the peripheral cells arise, and then periclinal walls (Pig. 

 53, 3), but beyond this no definite succession of walls could be 

 traced. 



The development of the spermatozoids is the same as in 

 other Liverworts. The slender body show's about two com- 

 plete coils; the vesicle is small, but always present, and the 

 cilia somewhat longer than the body (Fig. 53, F). The stalk 

 of the anther idium is long and at maturity composed of two 

 rows of cells. Before the central cells of the antheridium are 

 separated from the peripheral ones, the stalk shows a division 

 into two tiers of two cells each (Fig. 52, B), but it is only the 

 lower one that forms the real stalk ; the other forms the base 

 of the antheridium itself. The cells of the walls have numer- 

 ous chloroplasts, but the great mass of colourless sperm cells 

 within make the ripe antheridium look almost pure white. If 

 one of these is brought into water it soon opens in a very char- 

 acteristic way. The cells of the wall absorb water with great 

 avidity, and finally the upper part bursts open by a number of 

 irregular lobes wdiich curl back so strongly that many of the 

 marginal cells become completely detached. The whole mass 

 of sperm cells, with the included spermatozoids, is forced out 

 into the water, and if they are perfectly mature, the spermato- 

 zoids are quickly hberated and swim away (Fig. 53, D.) 



The female plants are decidedly larger than the males, but 

 the archegonial branches are much less conspicuous than the 

 antheridial ones. The older ones, w^hich either contain a 

 young sporgonium or abortive archegonia, are readily distin- 

 guished on account of the large perianth (Fig. 49, A), but 

 those that contain the young archegonia are situated very near 

 the apex of the main shoot, and are scarcely to be distinguished 

 from the very young vegetative branches. However, a plant 

 wnth the older perichsetia, or very young sporogonia, will usu- 

 ally show young archegonial branches as well. 



The archegonial branch originates in the same way as the 

 vegative branches, and the first divisions of its apical cell are 

 the same ; but only two or three segments develop leaves, after 

 which each young segment divides into an inner and an outer 

 cell ; the latter becomes at once the mother cell of the young 

 archegonium. The inner cell divides further by a transverse 

 wall, and the outer of the two cells thus formed gives rise to 



