LIST OF ILLUSTRATIONS. 



FIG. PAGE 



I. Duckmole (Ornithorhynchus) ..... 2 



z. Phenacodus, a primitive extinct Mammal (Cope) . 3 



3. Extinct moa and modern kiwi (Cams Sterne) . . 3 



4. Crocodiles ....... . . 4 



5. Salamander, an Amphibian ... 5 



6. Queensland dipnoan (Ceratodus) . . 5 



7. Amphioxus (Haeckel) ... . . 6 



8. Ascidian or sea-squirt (Haeckel). . . . 7 



9. Cephalopod (paper nautilus, female) .... 9 



10. Fresh-water crayfish (Astaais), a Crustacean (Huxley) 9 



11. a, Caterpillar ; b, pupa ; c, butterfly ... .9 



12. Spider ..... 10 



13. Crinoid or feather-star ... 10 



14. Earthworm ... . . II 



15. Bladderworm stage of a Cestode (Leuckart) . . 11 



16. Sea-anemones on back of hermit-crab (Andres) . 12 



17. Fossil Foraminifera, Nummulites . . . . .13 



18. Diagrammatic expression of classification in a genealogical 



tree .... IS 



19. Structure of the cell (Carnoy) . ... 44 



20. Fertilised ovum of Ascaris (Boveri) . . -45 



21. Diagram of cell division (Boveri) .... 45 



22. Karyokinesis (Flemming) -47 



23. Diagrammatic expression of alternation of generations . 54 



24. Diagram of ovum, showing diffuse yolk granules . 56 



25. Forms of spermatozoa (not drawn to scale) . 57 



26. Diagram of maturation and fertilisation. (From " Evolution 



ofSex") .... . .58 



27. Spermatogenesis and polar bodies (Hertwig and Weismann) 60 



28. Fertilisation in Ascaris megalocephala (Boveri) . . 61 



29. Modes of segmentation ....... 63 



30. Life history of a coral, Monoxenia darwinii (Haeckel) . 65 



31. Embryos — (1) of bird; (2) of man (His) .... 68 



32. Gradual transitions between Paludina iieumayri (a) and 



Paludina hoemesi (/) (Neumayr) ..... 76 



