XIV 



LIST OF ILLUSTRATIONS 



PLATE 29. A. Male and female seventeen-year cicada. B. Staghorn beetle, 



males and female Following 50 



PLATE 30. Male and female Hercules beetle " 50 



FIG. 7. Heads of male and female beetles 52 



PLATE 31. Male, female, and larva of Chauliodes cor nut us . . Following 52 



PLATE 32. Male and female fish : A. Callionymus lyra. B. Xiphophorus 



heller ii ......... Following 52 



PLATE 33. A. Male and female dragon-fly (Calopteryxmaculatd). B. Male, 



female, and larva of crested newt {Triton cristatus) Following 52 



PLATE 34. Males and females of different species of lizards " 52 

 FIG. 8. Secondary sexual characters in copepods . . . ; . -57 



FIG. 9. Locusts from the Galapagos Islands 62 



FIG. 10. Map of Oahu, Hawaiian Islands 64 



FIG. ii. Viola cucullata 88 



FIG. 12. Viola rostrata 89 



FIG. 13. Solea concolor .......... 90 



FIG. 14. Skeletons of the fore limbs of various vertebrates ... 92 



FIG. 15. Vestigial bones of the hind limbs in a boa constrictor . . 94 



FIG. 1 6. Skeleton of Greenland whale ....... 94 



PLATE 35 . Apteryx australis Following 94 



PLATE 36. Eyes of various vertebrates, showing the nictitating membrane 



Following 94 



PLATE 37. Hair tracts on the arms and hands of a man and a male chim- 

 panzee Following 94 



FIG. 17. Muscles of the human ear 95 



FIG. 1 8. Three fishes, showing stages in the loss of eyes and color . . 95 



FIG. 19. Stages in the development of the pond snail (Lymri&us) . . 97 



PLATE 38. Embryos of various vertebrates ..... Following 98 



FIG. 20. Tadpole of salamander ........ 98 



PLATE 39. American lobster ....... Following 98 



PLATE 40. A. Central nervous system of crawfish. B. u Blue crabs 11 " 98 



PLATE 41. A. " My sis stage 1 ' in the development of the American lobster. 



B. My sis stenolepis. C. Leg of My sis stenolepis . Following 98 



FIG. 21. Three stages in the development of a crab 100 



FIG. 22. Hydra. A diagrammatic longitudinal section . . . . 101 

 FIG. 23. Gastrula of a coral polyp (Monaxenia darwinii) . . . .102 



PLATE 42. Longitudinal sections of gastrulae of : A. frog, young. B. frog, 



older. C. chick Following 102 



FIG. 24. Longitudinal sections of gastrulas of various animals . . . 103 



PLATE 43. Antlers of a stag, showing the addition of new branches in suc- 

 cessive years ....... Following 106 



FIG. 25. Fossil deer antlers 107 



FIG. 26. Successive forms of Paludina from the tertiary deposits of Slavonia 108 



PLATE 44. Archcsopteryx lithographica Following 108 



PLATE 45. Fossil skeletons of: A. Hesperornis regalis. B. Ichthyornis 



victor. C. Phrodactylus spectabilis . . . Following 108 



FIG. 27. Skeleton of a crow no 



