480 The Philippine Journal of Science 1922 
JANETOSPHAERA AUREA (Ehrenberg) comb. nov. 
Volvox aureus Ehrenberg 1831 (fide Cohn). 
Volvoz globator Ehrenberg ex parte (fide Klein). 
Volvox minor Stein 1854. 
Volvox dioicus Cohn 1875. 
Mature coenobia very variable in size according to habitat, 
and even in the same locality quite variable; 170 to 850,; 
coenobia of more than 500 » forming only a small fraction of 
all. 
Somatic cells average from 500 to 1,000, minimum about 
200, maximum about 4,400.1. Sexual coenobia mostly with more 
numerous cells than asexual coenobia of the same size. 
Somatic protoplasts 5 to 8 or sometimes 9 » in diameter, round, 
not crowded; chromatophores not extending into the connecting 
filaments; connecting filaments very slender, of about the same 
thickness as the cilia and sometimes in pairs or even threes 
between the same neighboring protoplasts. 
Gonidia round like the somatic cells,* about 20 to 30 » before 
the first division; connected with neighboring protoplasts by 
numerous protoplasmic filaments. Number of gonidia ranging 
according to habitat from 1 to 16, mostly 4 to 8 or 6 to 10. 
Bending to form the hollow sphere is already present in the 
4-celled stage; gonidia with development arrested in early stages 
occur only occasionally. 
Daughter coenobia reaching 200 to 250 » (sometimes 300 to 
350 ») diameter before birth. Protoplasts at this time already 
rounded and always separated from one another by gelatinization 
of the cell membranes. Gonidia and androgonidia frequently 
more or less advanced in development at this time. . 
Distinction between asexual and sexual coenobia not sharply 
maintained. Among asexual and sexual coenobia are coenobia 
*Zimmermann (21, p. 260) gives the cell numbers in material collected 
by him in the vicinity of Freiburg in Brunswick, Germany, in the spring 
of 1919 as mostly fairly uniformly 1,024. In rare cases he found 2,048- 
celled coenobia. In cultures that were deteriorating the cell numbers fell 
to as low as 256. These numbers are based on his opinion that in the 
development of the coenobia all the cells of the embryo formed from the 
gonidium undergo the same number of divisions. This should dispose of 
the assertion of some of the earlier authors, Goebel (’82), and Goro- 
schankin (’75), repeated by Oltmanns (’04) that the four cells forming the 
anterior polar group in the 16-cell stage do not undergo further division. 
*Zimmermann (721, p. 262) has shown that the gonidia are not differ- 
entiated from the somatic cells until after the last cell division by which 
the full number of cells of the coenobium is produced. 
