
6 BOTANICAL GAZETTE [JULY 
direction, about 2.5 times the length of the gamete. The length 
of the entire male gamete is 4.5 » (fig. 16, b). 
Development of the male gametangia—As stated above, male 
gametangia arise from superficial cells of the thallus. One of the 
j superficial cells divides, giving rise to 
a gametangium initial and a stalk cell. 
Often two or more subsequent divi- 
sions occur and there is produced a 
filament of two or more cells, the 
terminal one of which is a male game- 
tangium initial (fig. 5,a,b,c). Inrare 
cases a filament becomes a long mul- 
ticellular hair consisting of a single 
row of cells, and some cell in the 
middle of the hair becomes the game- 
tangium initial. This shows that the 
male gametangium is a hair in origin 
(fig. 3, c,d). This development of a 
male gametangium from a single su- 
perficial cell, occurring simultaneously 
in multitudes of neighboring cells on 
large areas of the surface of the thal- 
lus, results in the production of thou- 
sands of gametangia growing side 
by side, producing the dark-colored 
patches upon the thallus. 
The nucleus of the male gametan- 
gium initial increases considerably in 
size. The chromatin network of the 
resting nucleus is marked by a number 
of knots mixed with fibrils. The 
chromatin knots increase gradually 
m.size in prophase and finally break 
moms bese anagem. When ch 
centrosome-like structures are a. 
‘ Present at the poles. Th lear 
membrane either persists or disa Pp e nucle 
Ppears at metaphase (fig. 6, a, b). 

