LIST OF ILLUSTRATIONS 



PAGE 



Ants Feeding in Their Nest .... Frontispiece 



1. Amoeba, Actinophrys, Spirogyra 21 



2. Volvox, Euglena, Peranema 35 



3. Paramecium, Vorticella, Didinium 41 



4. Sponges, Corals, Chaetodon, Ophiura .... 53 



5. Hydra 59 



6. Nereis 83 



7. Giant Spider Crab 101 



8. Leaf-Butterfly 115 



9. Mytilus, Squid, Obelia, Pennaria, Chordates . . . 141 



10. Axolotl 151 



11. Brontosaurus 177 



12. Frontispiece from Harvey's De Generatione Animalium . 223 



