viii CONTENTS 



CHAPTER VI 



EARLY DEVELOPMENT OF THE CHICK 66 



Cleavage . ... .... . . . . . . 67 



Gastrulation . . . . . . . . . , -. . . 70 



Origin of the Mesoderm . . . ..... ."' 77 



Body Form. . . . . . . . . :, . . . 81 



References for Further Study . 82 



CHAPTER VII 



EARLY MAMMALIAN DEVELOPMENT 84 



Cleavage 85 



Ectoderm and entoderm 88 



Mesoderm 93 



The Germ Layers in Man 99 



References for Further Study 106 



CHAPTER VIII 



DEVELOPMENT OF THE EXTERNAL FORM OF THE BODY 107 



General Form 107 



The Face 118 



The Extremities 121 



Age, Length and Weight of the Body 122 



References for Further Study 125 



CHAPTER IX 



THE DEVELOPMENT OF CONNECTIVE TISSUES AND THE SKELETAL SYSTEM. 129 



Histogenesis 131 



Fibers and Fibrils . ...''. 134 



Adipose Tissue. . . . . -. ;.-;>..- ,' 135 



Cartilage -. 136 



Osseous Tissue . . . . /'.-,.;, : .-".,. .'' . '. , , 137 



Intramembranous Ossification . . . . 137 



Intracartilaginous Ossification . 140 



The Development of the Skeletal System . .... '. 146 



The Axial Skeleton. . . . . . . . . . . ; 146 



The No tochord . .,...-. .... . . . . , I4 6 



The Vertebrae . . . . . . 1',". . . I47 



The Ribs. .' i v ... . ;. 152 



The Sternum ' . ^ 



The Head Skeleton 154 



Ossification of the Chondrocranium . 



