3iv CONTENTS. 



CHAPTER IX. PAGE 



DEVELOPMENT OF CONNECTIVE SUBSTANCE AND BLOOD (THE 



PARABLAST- AND MESENCHYME-THEORIES) . . . 170 



Historical ..-.. 189 



SUMMARY . . ... . 1 ' S "... . .191 



CHAPTEE X. 



ESTABLISHMENT OF THE EXTERNAL FORM OF THE BODY . 194 

 SUMMARY 206 



CHAPTEE XI. 



THE FCETAL MEMBRANES OF REPTILES AND BIRDS . . .206 

 SUMMARY - 220 



CHAPTEE XII. 



THE F(ETAL MEMBRANES OF MAMMALS 221 



SUMMARY . 238 



CHAPTER XIII. 



THE F(ETAL MEMBRANES OF MAN 241 



(1) THE CHORION 248 



(2) AMNION 250 



"(3) YOLK-SAC 251 



(4) DECIDUJE 252 



(5) PLACENTA 258 



(6) UMBILICAL CORD 268 



SUMMARY 272 



PART SECOND. 



CHAPTEE XIV. 

 THE ORGANS OF THE INNER GERM-LAYER. THE ALIMENTARY 



TUBE WITH ITS APPENDED ORGANS 281 



I. THE FORMATION OF THE MOUTH, THE THROAT-, GILL-, OR 



VISCERAL CLEFTS, AND THE ANUS 282 



II. THE DIFFERENTIATION OF THE ALIMENTARY TUBE INTO 



SEPARATE REGIONS, AND FORMATION OF THE MESENTERIES 295 

 III. THE DEVELOPMENT OF THE SEPARATE ORGANS OF THE ALL 



MENTARY TUBE . .304 



A. The Organs of the Oral Cavity : Tongue, Salivary Glands, and 



Teeth . . 304 



. The Organs arising from the Pharynx . . , . .313 



(1) The Thymus 314 



(2) Thyroid Gland . . . . . . . .317 



(3) Lungs and Larynx 320 



C. The Glands of the Small Intestine 324 



(1) The Liver .......... 324 



(2) Pancreas . . . 332 



SUMMARY . . . . ... . . . . . .333 



