34 MARCUS M. HARTOG. 
in the great transformation it undergoes. There can be no 
doubt that the “inner cell” of the male antheridium is a true 
gametogonium, since all its brood-cells become functional 
gametes; and as the “inner cell” of the archegonium is the 
homologue of that of the antheridium, we have here an addi- 
tional reason for regarding the former as a gametogonium, 
and the neck canal-cells as the outcome of degraded gametes ; 
for we must remember that these are of a lower generation than 
the belly canal-cell and oosphere. 
2. Vascular Cryptogams. 
In Vascutar Cryprocams generally the antheridium re- 
sembles that of Muscinez inessentials ; but the archegonium 
is somewhat different, for the initial cell only forms the neck- 
wall and inner cell, the belly-wall being formed by a sort of 
epithelial wali segmented off theadjacent cells of the prothallus.1 
Moreover, the divisions of the inner cell are often symme- 
7 N! (neck-canal cell) Ce} neck-canal cells. 
N (inner cell). 
N! (central cell) . i N? (belly-canal cell). 
i NN? (oosphere). 
Fic. 8.—Schema of divisions of inner cell of Vascular Cryptogams. 
trical, for the primitive neck-canal cell undergoes at most only a 
single bipartition.*” Thus by two bipartitions are formed four 
gametes, one functional, three degraded. The parallel with the 
formation of the polar bodies in the Metazoan ovum is com- 
plete so far as numbers go; and if we had only the Metazoan 
ovum and the archegonium of the Vascular Cryptogam to deal 
with, we might admit the conclusion, advocated especially by 
Maupas, that two and only two mitoses are requisite to dif- 
ferentiate the female pronncleus. But in Pilularia the 
central cell remains undivided, according to Campbell, and 
1 Sometimes, however, a basal cell is formed from the initial, and closes 
the belly of the archegonium below. 
2 In many cases it remains undivided. 
