1913] YAMANOUCHI—ZANARDINIA 17 
presents a striking likeness to the young plant of Zanardinia in 
nature, as it occurs thickly on the rock or broken wooden blocks in 
sea water. 
Germination of the unfertilized female gamete 
As previously stated, the female gametes after their discharge 
from the gametangia may come to rest very shortly or swim for as 
long a time as one hour. At the end of the movement, the female 
gamete becomes spherical. If the female gametes have failed to be 
caught by the motile male gametes, they remain as motionless, 

Fic. 15.—Portions of mature female gametangia: a, longitudinal section; b and 
¢, Cross sections. 
spherical bodies for a considerable time. If they have been 
fertilized, their nuclei may divide within 24 hours, but when 
fertilization has not occurred, mitosis is delayed. Even 30 hours 
after the quiescence, no wall has been recognized (fig. 50). About 
46 hours after quiescence a thin wall is developed, and when about 
48 hours old, nuclear division begins (figs. 52-57). Every phase 
in this division is typical and the number of chromosomes is clearly 
22 (figs. 52, 55). The elongation of the sporeling begins about 
46 hours after quiescence. At the 2-celled stage, one of the two 
cells which has a thickened wall at its free surface divides once or 
not any farther, and the cell corresponds to the elongated portion 
of the sporeling at the unicellular stage. The other cell, which has 
