Chapter Page 



XXXVI. The Differentiation of the Somites 502 



XXXVII. The Development of the Fourth Day 508 



XXXVIII. The Coelom and the Mesenteries 536 



XXXIX. Development of the Fifth Day 538 



EMBRYOLOGY OF THE FROG 543-618 



XL. The General Embryology of the Tadpole as compared 



with that of the Chick 543 



XLI. The Digestive Tract ... 585 



XLII. The Mesodermal Somites 591 



XLIII. The Circulatory System 594 



XLIV. The Urogenital System. 605 



XLV. The Skeletal System 612 



MAMMALIAN EMBRYOLOGY 619-633 



XLVI. Mammalian Embryology 619 



Part III Comparative Anatomy. 634-886 



XLVII. Introduction to Comparative Anatomy 637 



XLVIII. Classification of Fishes, Amphibians, and Mammals. . . . 639 



XLIX. The Integument 664 



L. The Endoskeleton 681 



LI. The Digestive System 722 



LII. The Respiratory System 757 



LIII. The Circulatory System. 772 



LIV. The Urogenital System 806 



LV. The Muscular System 826 



LVI. The Nervous System 833 



PRONOUNCING INDEX-GLOSSARY . . 887 



