1899] DEVELOPMENT OF CRYPTOMITRIUM LES 
divides the primary cell into the stalk or pedicel cell and the 
antheridial’ cell proper. The antheridial cell thus formed is 
then divided into three cells (a, fig. 2) by two transverse divi- 
sions. The next two divisions are longitudinal medial and are 
at right angles to each other, so that each of the three original 
cells is divided into four. In many cases, however, only the 
two lower cells are divided in this way (4, fig. 2), the top cell 
remaining undivided for a longer time. The four cells formed 
from the central cell by these longitudinal divisions are each 
again divided longitudinally, thus separating the sperm cells 
_ from those that go to make up a portion of the antheridial wall 
 (¢,fig. 2). The upper and lower cells take no part in forming 
the sperm cells, but form, respectively, the upper and lower por- 
_ tions of the antheridial wall. The remainder of the development 
, does not differ materially from that of Fimbriaria Californica as 
| described by Campbell.t| The top of the antheridial wall is not 
prolonged, however, as in that species, but is only a single row 
, of cells, as in Marchantia. In fact, the full-grown antheridium 
; (¢, fig. 2) resembles very closely that of Marchantia. 
| oe Sporogonial receptacle, or carpocephalum, is of Leit- 
— «&eb's “Composite’”’ types The apical cell of the thallus forms 
the growing point of the receptacle, but instead of remaining a 
single cell it divides into two cells. Each of these again 
ne : like manner. Finally one of the four cells thus 
me ivides into two, so that there are five growing points. 
cases this last division does not take place, so that 
— ae Only four growing points. Five is the usual num- 
fue for I found only two specimens out of the great 
os ig sl aig examined that had only four growing points. 
: eptacles, 1S Somewhat emphasized in the half-grown 
ee Sine or, at this time, the lobes between the growing 
ol the sah ld developed than the rest, so that the undersice 
Ave Ptacle has five quite prominent projections or folds. 
“ceptacle develops, however, these disappear. 
“CAMPBELL, D, i: 
> Leitcer: Ubtersuc 
Mosses and Ferns 50, 51. 1895. 
hungen iiber die Lebermoose 6: 32. 
