Observations on the Genus Volvox in Africa. 469 



PLATE XIII. 

 V. capensis sp. nov., from the Cape Flats. 



FIG. 



A. Group of asexual and sexual colonies ; of the latter some show sperm plates 



and oospheres, the others ripening oospores. Several attacked by a fungal 

 (Chytridiaceous) parasite. x 40. 



B. Portion of a young asexual coenobium showing form of the cells, and a 



developing daughter colony. x 300. 



C. Young sexual colony. x 102. 



D. Asexual colony, polar view. x 83. 



E. Sexual colony with nearly mature oospores. x 65. 



PLATE XIV. 

 V. capensis sp. nov. 



A. From Belvedere Road, Cape Flats. Hot weather form, November 1930. x 30. 



B, C. From Scanlan's Vlei, Wetton Road. B, with 2 Rotifers and 6 eggs, x 83. 



C, attacked by fungus. x 40. 



D. Rotifer parasitic on Volvox (Wetton Road). Individual freed from the colony 

 (killed with osmic acid). x 400. 



PLATE XV. 

 V. capensis, from the Cape Flats. 



A. Living cells from the anterior pole. x 1000. 



B. Cells killed with iodine from the posterior pole of a nearly mature asexual 



colony. x 1000. 



C. Mature sperm globoid in side view ; D, the same in surface view. x 1000. 



E. Group of nearly ripe oospores in situ, x 500. 



F. Single oospore further enlarged. x 800. 



PLATE XVI. 

 V. capensis f. nov. rhodesiensis, from N'gamo. 



A. Group of young (and one mature) sexual colonies, with a single immature 



asexual colony. x 40. 



B. Sperm bundle in side view ; C, the same in surface view, x 1000. 



D. Young oogonium with sperms round the base. x 1000. 



E. Nearly mature oospore. x 750. 



