LIST OF ILLUSTRATIONS 



1. Ovum of a threadworm (from Carnoy) ..... 



2. Diagram of cell division (after Boveri) .... 



3. Diagram of cell structure (after Wilson) .... 



4. "Comet-form" of starfish (after Haeckel) 



5. Asexual reproduction of a sea-worm (after Milne- 



Edwards) .......... 



6. Diagram of ovum ....... faring 



7. volvox globator ......... 



8. Forms of spermatozoa ........ 



9. Diagram of germinal continuity (after Wilson) . 



10. Spermatogenesis and polar bodies (atfer Hertwig and 



Weismann) ........•• 



11. Diagram of reduction and amphimixis (after Ziegler) facing 



12. Fertilised ovum of ascaris (after Boveri) . . . . 



13. Diagram of maturation and fertilisation (from Ziegler) 



facing 



14. Chromatin elements of nuclei (after Pfitzner) 



15. Diagram of fertilisation in ascaris (after Boveri) 



16. A pollen grain with its nuclei (from Carnoy) 



17. Diagram of protoplasmic changes 



18. Varieties of wall-liz.\rd (after Eimer) 



19. Variations in wasp (after Kellogg and Bell) 



20. Variations in beetle (after Tower) . 



21. Mutation in medusoids ..... 



22. Mutations of hart's tongue fern (after Lowe) 



23. Karyokinesis (after Flemming) 



24. Leaves of willow (after Wiesner) . 



25. Devonshire pony with stripes (from Darwin) 



26. Varieties of domestic pigeon (after Darwin) 



27. Brine-shrimp, Artemia salina .... 

 27a. Tail-lobes of Artemia salina (after Schmankewitsch) 



28. Half-lop rabbit (from Darwin) . . . . • 



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