204 
DOUGLAS HOUGHTON CAMPBELL 
into a short basal cell which subsequently divides further to form the 
short stalk of the older antheridium, and a terminal cell which is nearly 
hemispherical and develops into the body of the antheridium. This 
hemispherical cell, as usual in the Jungermanniales, first divides by a 
vertical median wall, and in each of the two cells thus formed two in- 
tersecting walls next arise which separate an inner cell in contact with 
the original median wall, and two peripheral cells (fig. 4, B). In cross 
Fig. 5. A-E. Development of the archegonium, seen in longitudinal section; 
X 335. F. An old archegonium, which has not been fertilized; X 75. v. c, ventral 
canal cell; 0, egg cell. 
section, the pair of central cells, from which subsequently the sperm- 
cells arise, appear triangular in outHne (fig. 4, C). As in most other 
Jungermanniales, the peripheral cells divide by radial walls only, so 
that the wall of the antheridium remains permanently but a single cell 
in thickness. The further divisions in the central cells were not fol- 
lowed in detail but the final divisions result in the spermatocytes which 
are in pairs as has been described in various other Hepaticae. The 
details of spermatogenesis were not critically studied, as the material 
Pid not seem to be especially favorable for this purpose, and there was 
A. 
C 
