8 BOTANICAL GAZETTE [JULY 
the male gamete is mature, a portion of the free surface of the 
membrane of the mother cell dissolves so as to leave a pore, 
through which the gamete is discharged (fig. 8). The cilia of the 
gamete first protrude from the pore, keep moving for a while, and 
then the whole body of the gamete emerges and is set free. 
Mature female gametangia.—Mixed with male gametangia, there 
are developed female gametangia, which arise like the former from 
superficial cells of the thallus. The mature female gametangium 
consists of several tiers of mother cells, the number of tiers varying 
from 3 to 9 (figs. 2 and 4, a). Each tier comprises 2 or 4 mother 
cells, so that the output of gametes from a single female gametan- 
gium fluctuates between 6 and 36. The mature female gamete in 


Fic. 5-—Portions of thallus showing origin of male gametangium initial: a, b, c, 
2, 2 or 3, and 3 or 4 layers of superficial cells respectively, outermost of which in each 
case are male gametangia. 
