88 The Philippine Journal of Science 1922 
Volvox organisms so different from V. globator and V. aureus 
as to lack the intercellular protoplasmic connecting filaments. 
The question was answered for me by the early differentiation 
and large size of the asexual reproductive cells of this and of 
a related species. Carter described the asexual reproductive 
cells, the gonidia, as reaching a large size before undergoing 
segmentation. His figure of a gonidium (’59, pl. 1, fig. 4), which 
is reproduced on a larger scale in Plate 7, fig. 44, shows one 
that had reached a diameter of 85 ». However, he did not 
appreciate the fact that such large gonidia, prominent in the 
daughter coenobia long before birth (as shown in his fig. 1, 
reproduced in Plate 7, fig. 42), are differentiated from the so- 
matogenic cells (those which by division produce the somatic 
or vegetative cells) at a very early stage in the development of 
the embryo and remain large, while the somatogenic cells be- 
come smaller and smaller by the repeated divisions which produce 
the very numerous somatic cells. 
Carter’s account of the asexual reproduction seems to have 
been based on observations which failed to include the stages 
that commonly occur at night. Until I had made a few obser- 
vations on living material through the hours of the night, my 
own work was in a fair way to muddle up in a description 
of one “species” forms that I now consider generically dis- 
tinct. One of these forms I have already described under the 
name Campbellosphaera obversa (Shaw, ’19). Its most dis- 
tinctive character is a migration of the gonidia during the bowl 
stage of the embryo from the outside to the inside through the 
opening, or phialopore, just before the closure which converts the 
bowl-shaped embryo into a closed globular colony, or coenobium. 
The absence of such a migration is the important character that 
was revealed by the nocturnal study of the species which forms 
the subject of this paper. 
Taking as a basis the characters found in the material in 
hand, I propose a new genus, Merrillosphaera, dedicated to Elmer 
Drew Merrill, the most indefatigable investigator of the flora of 
the Philippine Islands and the Indo-Malayan region. Believing 
this material cospecific with Volvox carteri Stein, I shall call it 
Merrillosphaera carteri (Stein) comb. nov. with the designation mani- 
lana for the form or variety first to be described in sufficiently full 
detail to furnish a basis for the recognition of the proper status 
of the genus. A very similar form was described by Powers 
(08) under the name Volvox weismannia. It is both proper 
and convenient to reduce this to Merrillosphaera carteri var. weis- 
