CHAPTER Ⅰ．HISTORICAL SKETCH 17
PART Ⅰ．EARLY DEVELOPMENT 21
CHAPTER Ⅱ．THE CELL IN DEVELOPMENT 21
A．Mitosis 21
The Achromatic Figure 21
Phases of Mitosis 22
Prophase 22
The Metaphase 24
The Telophase 25
B．Gametogenesis 26
Gametogenes Defined 26
Phases of Gametogenesis 26
Meiosis 28
C．Fertilization 31
Definition 31
The Spermatozoon 31
Contact of Sperm and Egg 32
Fusion of Gametes 32
CHAPTER Ⅲ．CLEAVAGE 35
Cleavage Defined 35
Types of Ova 35
Types of Cleavage 35
Cleavage Planes 39
Cleavage Patterns 40
Radial Cleavage 40
Spiral Cleavage 40
Bilateral Cleavage 41
Irregular Cleavage 41
The Blastula 41
CHAPTER Ⅳ．GASTRULATION AND NOTOGENESIS 43
Definition 43
A．Amphioxus 43
Gastrulation 43
The Germ Layers 45
The Axial Organs and the Mesoderm 45
The Mesodermal Somites 48
B．The Frog 50
The Blastula 50
Gastrulation 50
Notogenesis 56
(a) Germ Layers 56
Axial Organs 58
C．The Chick 61
Early Development 61
Gastrulation 63
The Germ Layers 68
Axial Organs 69
D．The Mammal 71
Early Development 71
Germ Layers 73
Gastrulation 73
Axial Organs 74
CHAPTER Ⅴ．EMBRYONAL MEMBRANES 75
Introductory 75
A．The Chick 76
Later History of the Mesoderm 76
The Amniocardiac Vesicles 77
Later History of the Blastoderm 78
The Amnion 78
The Chorion 81
The Yolk-sac 84
The Allantois 84
The Albumen-sac 88
B．The Mammal 89
The Mammalian Embryo 89
The Mammalian Amnion 90
The Chorion 91
The Yolk-sac 92
The Allantois 93
The Placenta 94
PART Ⅱ．ORGANOGENY 101
CHAPTER Ⅵ．THE ALIMENTARY TRACT AND ITS DERIVATIVES 101
A．Amphioxus 101
Digestive Tract 101
B．The Frog 103
The Archenteron 103
The Stomodeum 105
The Fore-gut and its Derivatives 107
The Mid-gut and its Derivatives 114
The Hind-gut and its Derivatives 115
C．The Chick 116
The Stomodeum 116
The Fore-gut and its Derviatives 118
The Mid-gut 126
The Hind-gut 126
D．The Mammal 129
The Stomodeum 129
The Fore-gut and its Derivatives 131
The Mid-gut 135
The Hind-gut 136
CHAPTER Ⅶ．THE CENTRAL NERVOUS SYSTEM 137
Introductory 137
A．Amphioxus 143
The Brain 143
The Nerve or＂Spinal Cord＂ 144
B．The Frog 145
The Brain 145
The Prosencephalon 148
The Mid-brain or Mesencephalon 149
The Rhombencephalon 150
The Spinal Cord 150
C．The Chick 152
The Brain 154
The Prosencephalon 154
The Mesencephalon 157
The Rhombencephalon 158
The Spinal Cord 159
D．The Mammal 162
The Brain 162
The Prosencephalon 163
The Mesencephalon 164
The Rhombencephalon 164
The Spinal Cord 165
CHAPTER Ⅷ．THE PERIPHERAL NERVOUS SYSTEM 166
Introductory 166
The Cranial Nerves 166
A．The Frog 170
The Cranial Nerves 170
The Spinal Nerves 173
The Sympathetic System 174
The Sense Organs 174
The Olfactory Organ 174
The Eye 176
The Ear 178
The Lateral Line Sense Organs 180
B．The Chick 181
The Cranial Nerves 181
The Spinal Nerves 182
The Sympathetic System 183
The Sense Organs 184
The Olfactory Organ 184
The Eye 187
The Ear 188
C．The Mammal 192
The Cranial Nerves 192
The Spinal Nerves 193
The Sympathetic System 193
The Sense Organs 193
The Olfactory Organ 193
The Eye 194
The Ear 194
CHAPTER Ⅸ．THE VASCULAR SYSTEM 196
A．The Frog 196
Ⅰ．The Hemal System 196
Origin 196
The Heart and the Pericardium 197
The Arteries 199
The Veins 202
Ⅱ．The Lymphatic System of the Frog 205
Origin 208
B．The Chick 208
Ⅰ．The Hemal System 208
Origin 208
The Heart and the Pericardium 209
The Arteries 212
The Veins 215
C．The Mammal 220
Ⅰ．The Hemal System 220
Ⅱ．The Lymphatic System 221
CHAPTER Ⅹ．THE URINO-GENITAL SYSTEM 223
Introductory 223
General Structure 223
A．Excretory System 225
Ⅰ．The Frog 225
The Pronephros 225
The Mesonephros 227
Ⅱ．The Chick 229
The Pronephros 229
The Mesonephros 230
The Metanephros 231
Ⅲ．The Mammal 233
The Pronephros 233
The Mesonephros 233
The Metanephros 233
B．The Reproductive System 235
Ⅰ．The Frog 235
The Germ Glands 235
The Gonoducts 236
Ⅱ．The Chick 238
The Germ Glands 238
The Gonoducts 240
Ⅲ．The Mammal 241
C．The Adrenal Bodies 243
Ⅰ．The Frog 243
Ⅱ．The Chick 243
Ⅲ．The Mammal 244
CHAPTER Ⅺ．THE ENDOSKELETON 245
Introductory 245
A．The Frog 245
Axial Skeleton 245
Ⅰ．Vertebral Column 245
Ⅱ．The Skull 246
The Visceral Skeleton 248
The Appendicular Skeleton 250
B．The Chick 250
The Axial Skeleton 250
Ⅰ．The Vertebral Column and Ribs 250
Ⅱ．The Skull 251
The Visceral Skeleton 251
The Appendicular Skeleton 253
C．The Mammal 253
CHAPTER Ⅻ．SUMMARY 254
Gastrulation and Notogenesis 256
Embryonal Membranes 260
The Alimentary Tract and its Derivatives 262
The Central Nervous System 267
The Peripheral Nervous System 272
The Vascular System 276
The Urino-genital System 278
The Skeleton 280