642 Annals of the South African Museum. 



DESCRIPTION OF PLATES. 



The numbers in brackets are the index numbers of the negatives from which 



the photographs are taken. 



PLATE XXXVIII. 



A-C, E-F. V. Rousseletii. D. V. capensis. 

 FIG. 



A. Mature female colony, mucilaginous content of central hollow discoloured 



(yellowish) showing inner membrane (310). x 48. 



B. C. Mixed colonies. B, Abnormally shaped colony with 2 large daughters and 



a number of oospores (311). x 48. 



C. Young colony containing 7 developing daughters, several mature sperm 



globoids, and numerous developing male cells in all stages (249). x 65. 



D. F. capensis. Cells at anterior pole (living, unstained) focussed to show eyespots 



(559). x 1000. 



E. V ' . Rousseletii. Developing daughter colony showing attachment to parent (159). 



x30. 



F. Living cells from posterior pole of young colony (94). x 900. 



G. Part of mature asexual colony showing pore above a daughter colony (removed). 



Protoplasmic connections mostly not visible owing to faulty fixation. 

 Stained Delafield's Haematoxylin to show cell walls (32). x about 650. 



PLATE XXXIX. 

 A, B, and F. V. capensis. C-E. F. Rousseletii. 



A. Cell detail, equatorial plane, and portion of daughter colony shown in B, 



showing palisade of closely packed cells. Living (560). x 1000. 



B. Young daughter colony, living, in situ ; recently inverted, showing gonidia 



and part of the periphery of the parent (561). x 465. 



C. Escape of daughter colony. One in the act of escaping, pore left by another 



showing as a flattening on the right (24). x 45. 



D. Escape of daughter colonies ; group including the above with daughter now 



free, one with 3 daughters showing position whence fourth has escaped, and 

 a third with all the daughters gone (25). x 16. 



E. Portions of a female colony with 1 developing and 3 or 4 mature oospheres 



on left ; on right part of a male colony with 2 undivided male initial cells 

 (side and surface view) and a mature sperm globoid. Living (198). x500. 



F. V. capensis. Part of a colony showing ripening oospores, 2 with thick, smooth 



walls ; the rest normal, covered with stout conical spines (553). x 290. 



PLATE XL. 



Inversion of the daughter colony. 

 A, B. F. capensis. Preparation. 



A. Young daughter just prior to completion of cell-division, showing phialopore 



(153). x290. 



B. Colony with 8 daughters, living, showing denting preparatory to inversion. 



Lip of phialopore depressed, outline definite (547). x 80. 



