LIST OF ILLUSTRATIONS XV 



FIGURE TITLE PAGE 



78 Relation of the notochord to vertebrae 142 



79 A typical human vertebra 143 



80 Plan of tho Vertebrate limb skeleton 144 



81 Skeleton of a Mammal (Felis domesticd) 145 



82 Dissection of Yellow Perch (Perca flavescens) .... 148 



83 Dissection of Green Frog (Rana clamitans) 149 



84 Dissection of Pine Lizard (Sceloporus undulatus) . . . 150 



85 Dissection of domestic Pigeon (Columba livid) .... 151 



86 Dissection of Gray Squirrel (Sciurus carolinensis) . . . 152 



87 Sagittal section of human body 153 



88 Human alimentary canal and derivatives 155 



89 Chemical activities of the digestive tract 158 



90 A gland . . '. . 159 



91 Vascular system of a Shark 164 



92 Plan of the circulatory system of a Fish, Amphibian, and 



Mammal 165 



93 Paths of absorbed food 168 



94 Food and respiratory paths 170 



95 Transformations of the aortic arches 171 



96 Nephridium of an Earthworm 177 



97 Evolution of the urogenital system . . . . . . . 179 



98 Section of human kidney and ureter 180 



99 Simple receptor-effector system 184 



100 More complex receptor-effector system 184 



101 Simple reflex arc 184 



102 Differentiation of nerve cells . 185 



103 Nervous organization of intestinal wall 186 



104 Development of the Vertebrate brain 187 



105 Types of Vertebrate brains 189 



106 Nervous system of the Frog 190 



107 Paths of nervous impulses 193 



108 Differentiation of sense cells 194 



109 Membranous labyrinth of the ear 197 



110 Human ear 198 



111 Development of the eye 200 



112 Vertebrate eye (human) .' . . 201 



113 Uterus (human) 205 



114 Yeast cells 213 



115 Reproductive cell cycles 214 



116 Hydra, dividing 217 



117 Flatworm, dividing 217 



118 Obelia 



119 Body plan of polyp and medusa 219 



