52 DUDLEY MEMORIAL VOLUME 



to determine. The cytoplasm surrounding the nucleus becomes less and 

 less evident as the nucleus increases in size and it can no longer be clearly 

 recognized in the later stages of development, although there probably per- 

 sists a thin envelope of cytoplasm surrounding the posterior coils of the 

 spermatozoid. 



The blepharoplast at this time forms a short hooped prominence at 

 the forward part of the spermatozoid and merging insensibly into the delicate 

 cytoplasmic prominence which extends beyond the nucleus. The latter con- 

 tinues to elongate and become curved over in the plane of the division wall, so 

 that the older spermatozoid has the form of a flat coil. (Fig. 7, M.) 



When fully developed the sperm is a slender thread composed of two 

 complete coils and part of a third. In these later stages the double stain 

 of safranin and gentian violet failed to clearly differentiate the different parts, 

 the spermatozoid appearing almost uniformly stained. The two spermato- 

 zoids of a pair are very closely approximated (Fig. 7, M) and present a 

 very characteristic appearance. 



The cilia could be made out in a number of the older stages (Fig. 7, H), 

 but their exact origin and position could not be determined as accurately as 

 might have been wished. It is probable, however, that as in some other cases 

 which have been investigated, they begin to double up at an early stage and 

 arise somewhat back of the apex. Woodburn' in a recent paper states that 

 in Porella the anterior end of the spermatozoid shows a slight enlargement, 

 which he interprets as the blepharoplast. The cilia in this case arise a short 

 distance back of this enlarged part of the blepharoplast. No trace of it was 

 observed in Calycularia. 



ARCHEGONIUM. 



The female plants, as we have already seen, are decidedly larger than 

 the males, and are usually 20-30 mm. in length, with a breadth of from 

 10-12 rrnn. Like the male plants, they are usually unbranched, but it is 

 not uncommon to find them forked once. The position of the archegonia 

 is much like that of the antheridia, these being grouped on a sort of recep- 

 tacle. (Fig. 2, A.) As a rule, only one archegonial receptacle is formed, 

 but sometimes the thallus will resume its growth and a second one may be 

 formed near the apex. The archegonium appears to agree in all respects 

 with that of other Jungermanniales that have been investigated. (Figs. 8 

 and 9.) After a short stalk has been formed, the archegonium mother cell 

 divides by the usual three intersecting vertical walls into an axial cell and 



' Woodburn, W. L. Spermatogenesis in Certain Hepaticse. Ann. Bet., 25, 1911. 



