XIV CONTEXTS. 



CHAPTEE IX. PAC;E 



DEVELOPMENT OF CONNECTIVE SUBSTANCE AND BLOOD (THE 



PARABLAST- AND MESENCHYME-THEORIES) . . .170 



Historical 189 



SUMMAEY 191 



CHAPTEE X. 



ESTABLISHMENT OF THE EXTERNAL FORM OF THE BODY . 194 

 SUMMARY . 200 



CHAFTEE XI. 



THE F(ETAL MEMBRANES OF REPTILES AND BIRDS . . . 20(5 

 SUMMARY 220 



CHAPTEE XII. 



THE FCETAL MEMBRANES OF MAMMALS 221 



SUMMARY . 238 



CHAPTEE XIII. 

 THE FCETAL MEMBRANES OF MAN 241 



(1) THE CHORION 248 



(2) AMNION 250 



(3) YOLK-SAC ---. . .251 



(4) ., DECIDUJS . . ,. 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 ALI- 

 MENTARY TUBE 304 



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



Teeth 304 



B. 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 . ' . 3b2 



SUMMARY . 333 



