490 



Annals of the South African Museum. 



M 



FIG. 3. Volvox gigas. A-E, development of Androgonidium. 



A, two-celled, and B, four-celled stage ; C, cell division complete ; D, bundle 

 inverting (phialoporic view) ; E, inversion complete, cilia lengthening ; 

 F, G, optical sections of bundles of 32 and 128 spermatozoids respectively ; 

 H, largest-sized bundle (512 spermatozoids) viewed somewhat obliquely from 

 below ; J, phialoporic view, optical section ; K, spermatozoids found swarm- 

 ing in female colony ; L, M, spermatozoids swarming round oospores ; N, 

 ripe oospore. 



s, eyespot ; n, nucleus ; c.v., contractive vacuole. 

 K x 2000 ; other figures x 500 ; all approximately. 



(Plate XXX, C, D). They are long (11-17 /z) and of rather distinctive 

 form; as a rule there appears to be a central wider region (3-4 JJL) 

 with an elongated nucleus and narrower anterior and posterior 



