LIST OF ILLUSTRATIONS xix 



FIG. PAGE 



93. Gallus, embryo incubated 30 hours ..... 205 



94. Gallus, embryo incubated 30 hours seen in longitudinal 



section ......... 206 



95. Gallus, embryo incubated 30 hours seen in transverse section 



(posterior region) ....... 207 



96. Gallus, embryo incubated 30 hours seen in transverse section 



(anterior region) ........ 208 



97. Gallus, embryo incubated 36 hours ..... 209 



98. Gallus, embryo incubated 60 hours . . . . .210 



99. Gallus, formation of amnion . . . . . .212 



100. Gallus, 4 days incubated, showing allantois . . .214 



101. Gallus, formation of amnion, chorion, yolk-sac, and allantois 215 



216 

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223 



225 

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235 

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244 

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252 



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102. Gallus, relations of embryonic membranes 



103. Gallus, face of embryo 



104. Development of metanephros 



105. Section through metanephros 



106. Gallus, skeleton of limbs and girdles of embryos incubated 



5 and 9 days ....... 



107. Development of feather ...... 



108. Lepus, early stages of development .... 



109. Lepus, formation of the amnion .... 

 no. Lepus, relations of embryonic membranes and placenta 

 in. Lepus, section through placenta .... 



112. Development of hair ...... 



113. Developing dogfish, showing blastopore 



114. Hypogeophis, embryos showing blastopore 



115. Reptile, sections through blastoderm showing origin of 



blastopore ....... 



116. Human embryo, relations of embryonic membranes 



117. Perameles, section through placenta . 



118. Cow, section through placenta .... 



119. Cat, section through placenta .... 



120. Scyllium, development of denticles 



121. Development of teeth, in mammals . 



122. Development of teeth in the dogfish . 



123. Diagram showing methods of tooth-succession . 



1 24. Types of teeth ....... 



125. Lacerta, embryo showing relations of ccelom 



126. Bird, showing relations of ccelom 



127. Mammal, embryo showing relations of ccelom . 



128. Trout, development of chondrocranium 



129. Schematic chondrocranium .... 



130. Relations of splanchnocranium to neurocranium 



131. Osteolepis, skull 



132. Stegocephalian (Loxomma), skull 



133. Seymouria, skull 



134. Chelone, skull .... 



135. Testudo, skull .... 



136. Cotylosaur (Captorhinus), skull . 



137. Ichthyosaurus, skull . 



138. Varanus, skull .... 



139. Sphenodon, skull 



140. Columba, skull 



