22? The Philippine Journal of Science 1922 
nobia increase slowly in size throughout the entire period of 
growth. 
The oogonidia, according to Powers, are reproductive cells like 
the gonidia, with which they may be mixed in the same coe- 
nobium. The highest number counted in coenobia which con- 
tained them alone was nineteen. They become larger than the 
gonidia, reaching 51 to 54 yp. 
The oospores, according to Powers’s photographs, develop a 
thick smooth wall within which the somewhat smaller proto- 
plast is concentrically located. 
The name androgonidia I will here apply to those reproductive 
cells which give rise to the sperm spheres. They occur mixed 
with the other reproductive cells in various proportions. They 
were described by Powers as about 1 to 3 » smaller than the 
gonidia at the time of segmentation, and gave evidence of 
having cytoplasmic and nuclear structure different from that 
of the gonidia. They were found to segment more tardily than 
the gonidia to the extent that in their early stages the sperm 
spheres are one or two cell divisions behind the vegetative 
coenobia that develop from the gonidia. 
The sperm spheres formed from the androgonidia, according 
to Powers, are Eudorina-like spheres of 32, 64, 128, or 256 cells, 
all of which proceed forthwith to divide and form sperm plate- 
lets, there being no somatic or vegetative cells among them. 
They have only rudimentary cilia and no power of locomotion. 
During the development of the sperm spheres the diameter of 
the constituent cells does not fall below 6 », whereas in the 
vegetative spheres the somatic cells become as small as 3 py, 
though the reproductive cells appear to be about the size of 
the cells in the sperm spheres. The form of the sperm spheres, 
as before stated, was described as spherical, except when they 
were deformed by pressure. 
A sperm platelet consisting usually of thirty-two spermato- 
zoids though sometimes of sixty-four, is formed from each cell of 
the sperm sphere, the number of sperms being the same in 
all the platelets of a sphere. The sperm sphere with its plate- 
lets is functionally a compound antheridium and may be con- 
veniently so styled. 
The spermatozoids were described by Powers as compact, 
with spherical nuclei and terminal cilia (’07, p. 134). 
