1921] : VAMANOUCHI—CORALLINA 93 
escape from the conceptacle, float about freely in the water, and 
after becoming attached to a suitable substratum proceed to 
germinate. 
Germination of tetraspores 
The first nuclear division at the time of germination of the 
tetraspores shows twenty-four chromosomes. The same is true 
for. the second and third divisions. With:culture material the 
size of the plants obtained from germinating tetraspores was 
limited to thirteen cells. Throughout all these divisions there 
was no change as regards the number of chromosomes. The infer- 
ence, therefore, is that such tetraspores, in nature, would give rise 
to sexual plants of normal size, possessing twenty-four chromosomes. 
Formation of antheridium 
The disk cell divides into two portions. The upper portion, 
which ultimately becomes the antheridium, is much smaller than 
the lower one; and is situated to one side of the latter. The two 
cells gradually become considerably elongated, the upper cell con- 
tinuing to elongate until it finally attains a remarkable length. At 
the same time its nucleus divides, one daughter nucleus migrating 
to the extreme distal portion of the cell, while the other daughter 
nucleus remains in the lower portion. Just below the upper daugh- 
ter nucleus a cell wall is formed, dividing the original upper cell into 
a very short terminal cell and a very long lower cell. The terminal 
cell becomes much enlarged and assumes a spherical form; the 
nucleus also enlarges greatly and occupies the larger portion of 
the cell. Thus the antheridium of Corallina is composed of a 
larger, spherical, terminal cell and a very much elongated, narrow, 
stalk cell. Later this spherical cell separates from the filiform 
stalk cell and functions as the spermatium. More than one antheri- 
dium may be formed from the same disk cell. The antheridial 
nuclei have constantly twenty-four chromosomes. The sperma- 
tium has a thin cell wall derived entirely from the mother cell, and 
when compared with other Florideae it is homologous with a 
unicellular antheridium. In 1911 SvEDELIUS, after having studied 
Delesseria, reported that the spermatium simply consists of the 
