96 BOTANICAL GAZETTE [AUGUST 
2. During the formation of tetraspores the forty-eight chromo- 
somes become reduced to twenty-four. The tetraspores on ger- 
mination show twenty-four chromosomes, and since twenty-four 
chromosomes appear in the vegetative mitoses of the sexual plants, 
the inference is that the latter arise from tetraspores. 
3. The nuclei of the reproductive cells (spermatia and carpo- 
gonia) of the sexual plants possess twenty-four chromosomes. The 
sporophytic or fusion nucleus, as a result of fertilization, has forty- 
eight chromosomes. ‘The sporophytic nuclei give rise by division 
to the carpospores, which also possess forty-eight chromosomes. 
The carpospores on germination show forty-eight chromosomes, 
and since forty-eight chromosomes appear in the vegetative mitoses 
of the tetrasporic plants, it is inferred that the tetrasporic plants 
originate from carpospores. 
4. The male and female waite 4 are gametophytic, while the 
tetrasporic plants are sporophytic. The sporophytic generation 
begins with the formation of the sporophytic or fusion nuclei, 
extends through the formation of the cystocarp and carpospores, 
and finally terminates with the formation of tetraspores on the 
tetrasporic plant. With the formation of the sige tacit the 
gametophytic generation commences. 
5. Thus Corallina is another clear example of the alternation 
of a sexual plant (gametophyte) with a tetrasporic plant (sporo- 
phyte), the cystocarp occurring as an early phase of the sporophytic 
generation. 
Toxyo HicHer NorMAL ScHOOL 
Toxyo, JAPAN 
