450 Annals of the South African Museum. 



to arrive at any clear idea as to the conditions governing the appear- 

 ance of any one species. 



As a whole, the material of F. capensis is very like that described 

 above from N'gamo, but there are a few points which may be noticed 

 here. The variation in the size of the protoplasts is even more marked 

 than in the N'gamo material. The number of sperm bundles is 

 greater, as many as 35 having been counted in a single large coenobium. 

 The oospores, on the other hand, although very large, have as a rule 

 relatively shorter spines, and are more like the Flats form than are 

 those from N'gamo ; in some localities, however, the longer-spined 

 form also occurs. 



Dimensions of V. capensis f. rJtodesiensis from the Linyanti Kiver. 



Asexual colonies, 625 x 667 ^ to 1323 x 1357 /*. 

 Sexual colonies, 539 x 646 p to 1252 x 1313 /*. 

 Daughter colonies, 322 x 344 n ; 5 to 19 in number. 

 Somatic protoplast, 5 to 10 [JL. 



Sperm globoids, 32 to 38 /u, ; (?) 7 to 35 in number. 

 Oospore with spines, 58 to 70 /z ; without spines, 43 to 53 fj, ; 

 spines, 7 to 11 ^. 



Before concluding our notes on F. capensis we wish to draw atten- 

 tion to the resemblance between it and V. barberi Shaw,* which, 

 however, appears to have a somewhat different cell structure. We 

 have had the opportunity of examining some of Shaw's Philippine 

 material, and we find that the spines which he gives as about 4 /z high 

 really measure from 5 to 7 /*,, or even up to 9 /JL, numbers which agree 

 well with those found by us for F. capensis. In general appearance, 

 however, F. barberi is more like F. globator. 



D. Volvox Rousseletii G. S. West. 



West placed in this species the Volvox whose asexual f and sexual 

 colonies he obtained from the Ussangu Desert. The asexual colonies 

 were presumably considered by him to be identical with those he had 



* Shaw, W. R., loc. cit., vol. xx, No. 5, May 1922, p. 496. 



t West did not distinctly state, but left it to be inferred, that asexual colonies 

 from Ussangu were examined by him. Thanks to the kindness of Professor Stiles, 

 we have been able to examine West's slides of this material, and we find that 

 asexual colonies are present. (We have also been able to examine Mr. Rousselet's 

 slides of the VoJrox from Rhodesia, thanks to Mr. Scorn-field, to whom the slides 

 were lent by Mr. Bryce.) 



