Xll LIST OF ILLUSTRATIONS 



FIGURE PAGE 



117. Central Nervous System of Frog . ... 118 



118. Frog Eggs : ... 121 



119. Diagram Illustrating Fertilization in Frog Egg . . . .121 



120. Dividing Egg of Frog 122 



121. Dividing Egg Becoming a Tadpole 122 



122. Two Stages in the Development of Tadpoles .... 123 



123. Fossil Shells of Animals Now Extinct 124 



124. Tree Frog 126 



125. A Sea Turtle 129 



126. Horned Toad, a Lizard 129 



127. Bull Snake with Hen's Egg in Mouth 130 



128. Bull Snake after Swallowing Egg 130 



129. Head of Rattlesnake 131 



130. Rattles of Rattlesnake 131 



131. Rattlesnake — Poisonous 132 



132. Garter Snake — Harmless 133 



133. Eight-Foot Florida Alligator ....... 133 



134. Alligator Nest 134 



135. Poisonous Lizards ; the Gila Monster 135 



136. Grebe . . ... . • 136 



137. Herring Gulls 137 



138. Adult Screech Owl 138 



139. Skeleton of Mallard Duck .138 



140. Different Kinds of Birds' Feet ....... 139 



141. Loggerhead Shrike 139 



142. Young of Red-Tailed Hawk — Beneficial ..... 140 



143. Head of Young Eagle 140 



144. The Robin 141 



145. Nest of Yellow Warbler 142 



146. Nest of Bittern 142 



147. Mourning Dove . .143 



148. Chimney Swift and Nest „ 144 



149. Junco . 144 



150. Female Bobolink 145 



151. King Bird . 145 



152. Young Crows in Nest 146 



153. Kingfisher 146 



154. Hairy Woodpecker Eating Suet 147 



155. Male and Female Cowbirds 147 



156. Plan for Bird House 148 



157. Plan for Bird House .148 



158. Skeleton of Dog . 150 



