LIST OF FIGURES 



Fig. 12. 

 Fig. 13. 

 Fig. 14. 

 Fig. 15. 

 Fig. 16. 



Frontispiece — Jellyfish, Chrysaora, in Open Sea 



Fig. I. Genealogical Tree of Animals 6 



Fig. 2. Growth of Ear-shell 16 



Fig. 3. Scale of Bony Fish, showing lines of growth 17 



Fig. 4. Otolith and Opercular Bone of Bony Fish 18 



Fig. 5. Queen Termite, distended with eggs 20 



Fig. 6. Karyokinetic Cell-division 21 



Fig. 7. Adventitious Buds of Bryophyllum 24 



Fig. 8. Mermaid's Purse, with Young Dogfish 25 



Fig. 9. Variations of Hart's Tongue Fern. After Lowe 28 



Fig. 10. Storm Petrel on Open Sea 34 



Fig. ii. Pelagic Holothurian. After Chun 35 



Deep-sea Pennatulids, Chunella -and Umbellula 36 



Commensalism of Hermit-crab and Sea-anemone 44 



Large Deep-sea Pennatulid, Anthoptilum 47 



Diagram of Relations between Organism and Environment 49 



Variations in Potato-beetle. After Tower 50 



Fig. 17. Adaptations in Barnacles 51 



Fig. 18. Life-history of Salmon 81 



Fig. 19. Diagram of the Great Haunts of Life 83 



Fig. 20. Deep-sea Fish, Gastrostomus. After Murray and Hjort 84 

 Fig. 21. Sea-horse, Phyllopteryx, with seaweed-like tassels. After 



Gunther 85 



Fig. 22. Bullhead, Cottus scorpio; a littoral fish 86 



Fig. 23. Cavernicolous beetle 89 



Fig. 24. Eyes in newts 90 



Fig. 25. Dimorphism in Bilharzia worm. After Looss 91 



Fig. 26. Giant Lizard, Amblyrhynchus. After Beebe 94 



Fig. 27. Greenland Falcon 99 



Fig. 28. Jerboas in the desert 102 



Fig, 29. Diagram of Inter-relations of Termites 106 



Fig, 30. A Wasps' Nest iii 



Fig. 31. Female Paper Nautilus, swimming 112 



Fig. 32. Hermaphrodite Colony of Volvox 113 



Fig. 33. Division of Labour in Siphonophore Colony 114 



Fig. 34, Two Abyssal Pennatulids, Umbellula and Stachyptilum 116 



Fig, 35. Different Forms of Termites 118 



Fig. 36. Commensalism of Hermit-crab and Sea-anemone 134 



Fig. 37. Dimorphism in Bilharzia, After Looss 142 



Fig, 38, Dimorphism in Bonellia 143 



