21,2 Shaw: Copelandosphaera 219 
Volvox africanus West (’10) -which appears in West’s photo- 
micrographic figures and in photographs of some of my own 
material. The coenobia of that species are commonly more 
truly egg-shaped in having one end, the forward one, larger 
than the other, and are properly described as ovoid. In Cope- 
landosphaera spermatosphaera the ellipsoidal form is strongly 
marked in the young coenobia, and is evident before birth, 
except in the sperm spheres, which are spherical (Powers 07, 
p. 129). 
The size of the mature coenobia in Powers’s first collection of 
this species ranged between 500 and 1,000 pw. Material subse- 
quently collected in Nebraska gave maximum dimensions for 
mature coenobia with vegetative or mixed content of 600 to 
650 », and for coenobia with oospores alone of about 500 pw. The 
smallest coenobia containing mature sperm spheres were as 
small as 150 » or even smaller. The most frequent size of 
mature coenobia in a large collection from Missouri was not far 
from 350 ». In the larger mothers the size of the daughters 
at birth was about 250 »; in smaller ones they frequently escape 
at 100 » or less. 
The number of cells in the coenobia was estimated by Powers 
to be between 1,000 and 3,000. When coenobia with smaller 
numbers of cells produce daughters with larger numbers, the 
progeny, though present in medium or smaller numbers, fill the 
entire cavity of the mother and stretch the maternal coenobial 
wall out of its original shape. This was illustrated by figures 
of overcrowded mothers (Powers ’08, pl. 24, figs. 20, 23, and 
26). When, on the other hand, the number of cells in the 
daughter coenobia is the same as or less than the number in the 
mother there is ample room for the progeny in the posterior 
half or three-fifths of the mother. 
The somatic cells of the adult coenobia were stated by Powers 
to range from 6 to 10 », most of them being of the smaller size. 
The distance separating them was given as usually 28 to 40 uz, 
though sometimes as great as 50 ». The somatic cells in the 
daughters at the time of birth were stated to be about 5 By 
and Powers found that they increase to nearly or quite full 
size by the time the gonidia begin to divide. 
In shape the somatic cells were stated to resemble most 
the figures which Meyer gave for his Volvox tertius (Powers 
’07, p. 139, Meyer ’96, pl. 8, fig. Z), and like them they showed 
no signs of any connecting protoplasmic filaments between the 
neighboring protoplasts. From such observations as he made 
