Xviil CONTENTS 



Page 



Organogenesis in Amphioxus 8i 



Organogenesis in Vertebrates 85 



Neural Tube 85 



Notochord 86 



The Enteron 87 



The Mesoderm 91 



The Mesenchyme 102 



Connective Tissue 102 



Skeleton 103 



Muscle 106 



Circulatory Organs 106 



Head, Neck, Diaphragm, Tail 107 



Effect of Massive Yolk on Organogenesis 109 



Embryonic and Fetal Membranes 113 



Function of the Embryonic and Fetal Membranes 121 



Summary and Interpretation 122 



3. Histology 126 



Epithelial Tissues 129 



Simple Epithelium I3^^ 



Stratified Epithelium 132 



Glands i39 



Non-Epithelial Tissues 14° 



Muscular Tissue 141 



Nervous Tissue • ^45 



Tissues Serving for Mechanical Support 15° 



Connective Tissue iSi 



Skeletal Tissues iS3 



Notochord ■ • iS3 



Cartilage ^54 



Bone 158 



Adipose Tissue ■ ^S8 



Blood 158 



Histological Specificity 162 



4. The Integumentary System 164 



Evolution of the Skin 164 



Structure of the Human Skin 166 



Development of the Skin 167 



Finger-prints and Their Meaning 168 



Appendages of the Integument 169 



Horny Scales ^7° 



Horns ^7i 



Nails, Claws, and Hoofs i7i 



Feathers ^72 



Hairs ^73 



Pigment ^7^ 



Cutaneous Glands ^79 



5. Teeth ^^^ 



Evolution of Teeth 183 



Evolution of Compound Teeth 187 



