ILLUSTRATIONS 



XI 



FIG. PAGE 



74. AMPHIOXUS. CAUDAL END OF LARVA . . . 150 



75. KAIA. EMBRYOS TO ILLUSTRATE THE CHANGE FROM THE 



BOUND TO THE FLATTENED STATE . . . .155 



76. KAIA. PLACOID SCALE . . ^ . . . .157 



77. RAIA. VERTEBRAL COLUMN ... . . 158 



78. KAIA. VERTEBRAL COLUMN . . . . . 159 



79. ACANTHIAS. DEVELOPMENT OF SKULL . . . 160 



80. KAIA. SKULL 161 



81. KAIA. PECTORAL AND PELVIC GIRDLES . . . 162 



82. MYLIOBATIS. DEVELOPMENT OF TEETH . . . 164 



83. KAIA. GASTRIC GLAND 164 



84. KAIA. GENERAL DISSECTION 165 



85. KAIA. TRANSVERSE SECTION OF EMBRYO . . .167 



86. KAIA. DIAGRAM OF EMBRYONIC CIRCULATION . . 169 



87. KAIA. DIAGRAM OF CIRCULATION OF ADULT . .170 



88. KAIA. DIAGRAMS OF CIRCULATORY ORGANS . .171 



89. KAIA. BRAIN AND CRANIAL NERVES . . . .177 



90. RAIA. DEVELOPMENT OF EYE 180 



91. KAIA. DIAGRAM OF EYE 181 



92. RAIA. AUDITORY ORGAN 182 



93. ACANTHIAS. TRANSVERSE SECTION OF EMBRYO . . 186 



94. ACANTHIAS. TRANSVERSE SECTION OF EMBRYO . . 187 



95. FRISTIURUS. DIAGRAMS TO ILLUSTRATE DEVELOPMENT 



OF MESONEPHROS 188 



96. RAIA. REPRODUCTIVE ORGANS 189 



97. DIAGRAMS TO ILLUSTRATE DEVELOPMENT OF ELASMO- 



BRANCHS . . . . . ..;' . . . 192 



98. RANA. DEVELOPMENT OF VERTEBRA . . . 198 



99. RANA. CARTILAGINOUS SKULL OF YOUNG TADPOLE . 199 



100. RANA. CARTILAGINOUS SKULL OF OLDER TADPOLE . 200 



101. RANA. DORSAL VIEW OF SKULL .... 201 



102. RANA. VENTRAL VIEW OF SKULL .... 202 



103. RANA. PECTORAL GIRDLE 203 



104. RANA. PELVIC GIRDLE 205 



105. RANA. GENERAL DISSECTION 206 



106. RANA. DIAGRAMS OF ARTERIAL AND VENOUS SYSTEMS 210 



107. RANA. DIAGRAM OF HEART . . . . .211 



108. RANA. BRAIN . 215 



109. RANA. CRANIAL NERVES . . . . . .218 



110. RANA. AUDITORY ORGAN 221 



111. RANA. PRONEPHROS AND DEVELOPING MESONEPHROS 



OF TADPOLE . . ... . . . 222 



112. RANA. Two STAGES IN DEVELOPMENT OF MESONEPHRIC 



TUBULE . 223 



113. RANA. REPRODUCTIVE ORGANS 224 



114. RANA. SEGMENTATION OF EGG 225 



115. RANA. GASTRULA AND POST-GASTRULA STAGES . 227 



