524 Annals of the South African Museum. 



Reproduction continued. 



Development of Reproductive Cells continued. PAGE 



A. Gonidium continued Results of Inversion . 577 



Time of Inversion ........ 578 



Discovery of Inversion ..... . 579 



Daughter Colony . . -582 



(a) Development after Inversion ... . . 582 

 (6) Birth . . 583 



B. Male Initial Cell . . .585 



1. V. Roussdetii . . 587 



Enlargement .... . 587 



Shifting of Polar Axis ... ... 587 



Division . 588 



Preparation for Inversion ...... 590 



Inversion ......... 592 



Sperm Globoid, Maturation ...... 593 



Escape ......... 594 



Life Free in AVater 596 



Escape of Sperms. ....... 596 



Structure of Sperms ....... 598 



2. V. capensis ......... 599 



C. Female Initial Cell 601 



Enlargement ......... 601 



Mature Oosphere ........ 603 



Homologies of the Reproductive Cells ...... 603 



Fertilisation ........... 606 



Oospore, Development after Fertilisation ...... 609 



Size and Appearance in the Two Species ... . 610 



Liberation ........ 611 



Juvenile Form, Discovery . . . . . . . .612 



Oospore Cultures ; Collection of Oospores . . . . .614 



Culture Methods and Results . . . . . . .614 



Germination of Oospore . . . . . . . .616 



Zoospore, Structure . . . . . . . . .617 



Division ........... 620 



Inversion of the Germ Colony ....... 622 



Appearance after Inversion ........ 624 



II. The Juvenile Form, Structure ........ 625 



Development of Second Generation ...... 626 



Previous Accounts of Germination . . . . . . . .627 



Discussion ............ 629 



1. Germination .......... 629 



2. Form of the Germ Colony Juvenile ...... 630 



3. The Process of Inversion . . . . . . . .631 



4. Variation in Number and Form of Cells . . . . .631 



5. Systematic Aspect ......... 632 



Summary ............ 633 



Appendix Oospore Cultures ......... 636 



Note Volvox from Grahamstown . ..... 638 



Bibliography . .... 639 



Description of Plates . . . .... 642 



