1921] YAMANOUCHI—CORALLINA 95 
it, and discharges its contents into it. The trichogyne nucleus now 
begins to disintegrate. The spermatium nucleus proceeds down- 
ward, finally reaching the carpogonial nucleus, with which it fuses. 
At this time the auxiliary cell unites with the auxiliary cells of 
adjacent procarps, resulting in the formation of a large central cell 
within the conceptacle. The passage between this central cell and 
the carpogonium broadens. The sporophytic or fertilized carpo- 
gonial nucleus now passes into the large central cell. Since the 
sporophytic nuclei of all the procarps within the conceptacle 
migrate into this central cell, there are therefore over 100 sporo- 
phytic and also about the same number of gametophytic or auxil- 
iary cell nuclei included in this common cytoplasm. The two 
kinds of nuclei found in the central cell differ as regards their 
structure. The sporophytic,nuclei are usually large, rich in chro- 
matin, and possess forty-eight chromosomes; the gametophytic 
nuclei are small, possess twenty-four chromosomes, and most of 
them gradually disintegrate. 
Each sporophytic nucleus moves to the periphery of the central 
cell, where it divides to form two nuclei. One nucleus enters the 
cell which has been formed on the outer surface of the central cell, 
while the other nucleus remains inside the central cell. From the 
cell produced on the external surface of the central cell, a chain of 
cells is formed in basipetal sequence. These cells enlarge, become 
spherical, and when they have attained the size of tetraspores, 
gradually become constricted, separate, and finally escape from the 
conceptacle as carpospores. 
Germination of carpospores 
After the carpospores have escaped from the conceptacle, they 
begin to germinate within twenty-four hours. The first nuclear 
division is of the normal type and shows forty-eight chromosomes. 
The same is true of the second and third divisions. ‘The sporelings 
continue to develop until the 17-celled stage is reached, all of the 
cell divisions being of the normal type and showing constantly 
forty-eight chromosomes. 
1. The male and female plants of Corallina possess twenty-four 
chromosomes, while the tetrasporic plants have forty-eight chromo- 
somes. 
