FIGURE 1.50. GASTRULATION OF THE LAMPREY. FIGURE 1.51. GASTRULATION OF CERATODUS. FIGURE 1.52. OVUM OF A DEEP-SEA BONY FISH. FIGURE 1.53. SEGMENTATION OF A BONY FISH. FIGURE 1.54. DISCOID GASTRULA OF A BONY FISH. FIGURES 1.55 AND 1.56. SECTIONS OF BLASTULA OF SHARK. FIGURE 1.57. DISCOID SEGMENTATION OF BIRD'S OVUM. FIGURES 1.58 TO 1.61. GASTRULATION OF THE BIRD. FIGURE 1.62. GERMINAL DISK OF THE LIZARD. FIGURES 1.63 AND 1.64. GASTRULATION OF THE OPOSSUM. FIGURES 1.65 TO 1.67. GASTRULATION OF THE OPOSSUM. FIGURES 1.68 TO 1.71. GASTRULATION OF THE RABBIT. FIGURE 1.72. GASTRULA OF THE PLACENTAL MAMMAL. FIGURE 1.73. GASTRULA OF THE RABBIT. FIGURES 1.74 AND 1.75. DIAGRAM OF THE FOUR SECONDARY GERMINAL LAYERS. FIGURES 1.76 AND 1.77. COELOMULA OF SAGITTA. FIGURE 1.78. SECTION OF YOUNG SAGITTA. FIGURES 1.79 AND 1.80. SECTION OF AMPHIOXUS-LARVAE. FIGURES 1.81 AND 1.82. SECTION OF AMPHIOXUS-LARVAE. FIGURES 1.83 AND 1.84. CHORDULA OF THE AMPHIOXUS. FIGURES 1.85 AND 1.86. CHORDULA OF THE AMPHIBIA. FIGURES 1.87 AND 1.88. SECTION OF COELOMULA-EMBRYOS OF VERTEBRATES. FIGURES 1.89 AND 1.90. SECTION OF COELOMULA-EMBRYO OF TRITON. FIGURE 1.91. DORSAL PART OF THREE TRITON-EMBRYOS. FIGURE 1.92. CHORDULA-EMBRYO OF A BIRD. FIGURE 1.93. VERTEBRATE-EMBRYO OF A BIRD. FIGURES 1.94 AND 1.95. SECTION OF THE PRIMITIVE STREAK OF A CHICK. FIGURE 1.96. SECTION OF THE PRIMITIVE GROOVE OF A RABBIT. FIGURE 1.97. SECTION OF PRIMITIVE MOUTH OF A HUMAN EMBRYO. FIGURES 1.98 TO 1.102. THE IDEAL PRIMITIVE VERTEBRATE. FIGURE 1.103. REDUNDANT MAMMARY GLANDS. FIGURE 1.104. A GREEK GYNECOMAST. FIGURE 1.105. SEVERANCE OF THE DISCOID MAMMAL EMBRYO. FIGURES 1.106 AND 1.107. THE VISCERAL EMBRYONIC VESICLE. FIGURE 1.108. FOUR ENTODERMIC CELLS. FIGURE 1.109. TWO ENTODERMIC CELLS. FIGURES 1.110 TO 1.114. OVUM OF A RABBIT. FIGURES 1.115 TO 1.118. EMBRYONIC VESICLE OF A RABBIT. FIGURE 1.119. SECTION OF THE GASTRULA OF FOUR VERTEBRATES. FIGURES 1.120 TO 1.123. EMBRYONIC SHIELD OF A RABBIT. FIGURE 1.124. COELOMULA OF THE AMPHIOXUS. FIGURE 1.125. CHORDULA OF A FROG. FIGURE 1.126. SECTION OF FROG-EMBRYO. FIGURES 1.127 AND 1.128. DORSAL SHIELD OF A CHICK. FIGURE 1.129. SECTION OF HIND END OF A CHICK. FIGURE 1.130. GERMINAL AREA OF THE RABBIT. FIGURE 1.131. EMBRYO OF THE OPOSSUM. FIGURE 1.132. EMBRYONIC SHIELD OF THE RABBIT. FIGURE 1.133. HUMAN EMBRYO AT THE SANDAL-STAGE. FIGURE 1.134. EMBRYONIC SHIELD OF RABBIT. FIGURE 1.135. EMBRYONIC SHIELD OF OPOSSUM. FIGURE 1.136. EMBRYONIC DISK OF A CHICK. FIGURE 1.137. EMBRYONIC DISK OF A HIGHER VERTEBRATE. FIGURES 1.138 TO 1.142. SECTIONS OF MATURING MAMMAL EMBRYO. FIGURES 1.143 TO 1.146. SECTIONS OF EMBRYONIC CHICKS. FIGURE 1.147. SECTION OF EMBRYONIC CHICK. FIGURE 1.148. SECTION OF FORE-HALF OF CHICK-EMBRYO. FIGURES 1.149 AND 1.150. SECTIONS OF HUMAN EMBRYOS. FIGURE 1.151. SECTION OF A SHARK-EMBRYO. FIGURE 1.152. SECTION OF A DUCK-EMBRYO. FIGURES 1.153 TO 1.155. SOLE-SHAPED EMBRYONIC DISK OF CHICK.