viii CONTENTS 



Page 



Mitosis 44 



A Study of the Basic Reproductive and Hekedity Phenomena. . 47 



Maturation and Fertilization 47 



A Study in Development 48 



Segmentation and Gastrulation of the Starfish's Egg 49 



Segmentation and Gastrulation of the Frog's Egg 50 



Larval Development of the Frog 54 



An Introduction to the Study of Inheritance 56 



A Study op Representatives of the Various Phyla 60 



Introduction 60 



Phylum Protozoa 61 



Amoeba 61 



Paramoecium 63 



A Study of Mixed Protozoan Cultures 67 



Introduction 67 



Key for the Identification of Protozoa 68 



Phylum Coelenterata 74 



Hydra 74 



Obelia 77 



Gonionemus 80 



Phylum Platyhelminthes 82 



Planaria 82 



Phylum AnneUda 85 



Nereis 85 



An Earthworm 87 



Phylum MoUusca 94 



Phylum Arthropoda 97 



A Crayfish (or a Lobster) 97 



A Grasshopper 102 



Phylum Chordata 106 



Subphylum Cephalochorda, Branchiostoma (Amphioxus) .... 106 



Subphylum Vertebrata HO 



A Shark, the Spiny Dogfi,sh 110 



A Bony Fish, the Yellow Perch HI 



A Review of the Phyla, Subphyla, and Classes op Animals . . .118 



'^Introduction 118 



A Key for the Identification of the Larger Groups of Animals . . . 118 



