434 Annals of (he South African Museum. 



4. The} 7 grow until they almost fill the internal cavity of the parent, 

 becoming flattened by compression ; they themselves show well- 

 developed daughter colonies long before their escape from the mother 

 colony, and even a fourth generation is not uncommon. 



5. The somatic protoplasts are almost globose, with long, delicate 

 protoplasmic strands (Shaw,* however, disputes the presence of these 

 strands, and in his earlier account West f states that no protoplasmic 

 connections could be observed). 



6. The number of oospores averages 74 (70 to 80) ; wall of oospore 

 thick and smooth. 



The diagnosis of this species was amplified by Shaw from material 

 collected near Manila in July 1914 and subsequently. He found no 

 protoplasmic connections between the cells ; in his material there 

 were sometimes as many as 6 or 8 daughter colonies, the oospores 

 varied from 12 to 43 per coenobium, measuring 43 to 45 JJL when ripe. 

 The oospores were sometimes associated with from 2 to 6 sperm plates, 

 but more usually the latter were found in colonies producing no other 

 reproductive cells (100 to 400 per coenobium). He was not able to 

 count the number of sperms evidently most of his antheridia were 

 still young but thought it was either 64 or 128 per platelet ; he gives 

 the dimensions of one antheridium in the 32-celled stage (26 /x) and of 

 one mature sperm plate (7 /x thick by 20 yu, wide). The antheridium 

 mother-cell often reached 19 /x before dividing to form a platelet or 

 hollow cup of sperms. According to West this African species differs 

 from F. aureus in the ovoid-ellipsoid shape of its asexual colonies, 

 in the larger number of constituent cells, and in the nature of the 

 daughter colonies. 



Volvox Rousseletii is described by West as follows : 



1. The asexual coenobia are large, having a diameter of from 

 1125 to 1240 jji when fully mature. 



2. The number of constituent cells is large, 25,000 to 50,000, and 

 they are rather closely aggregated. 



3. The somatic protoplasts are somewhat angular, with relatively 

 broad connecting strands. 



4. Daughter colonies regularly 8. 



5. The sexual colonies are dioecious. 



6. Sperm bundles are numerous. 



* Shaw, W. R., loc. cit., vol. xxi, 1922, p. 118; vol. xxii, 1923, pp. 189 

 and 197. 

 t West, G. S., loc. cit., 1910, p. 103. 



