LIBRARY 



CONTENTS 



Page 



Preface v 



1. The Animal Kingdom i 



The Linnaean System 2 



The Animal Phyla 3 



Summary of Classification 22 



Sequence of Organisms in Geologic Time 25 



2. Reproduction 26 



The Germinal Bodies 26 



Oviparity, Viviparity, Impregnation 30 



Protection, Nutrition, and Respiration during Development. 31 



Evolutionary Significance 3^ 



Development 3^ 



Cleavage and Blastula 3^ 



Gastrula 43 



Third Layer, Mesoderm 49 



Early Development in Placental Mammals 55 



Organogenesis 5^ 



Organogenesis in Amphioxus 58 



Organogenesis in Vertebrates 62 



Relation of Yolk to Organogenesis 78 



Embryonic and Fetal Membranes 80 



3. Histology 85 



Epithelial Tissues 86 



Glands 91 



Non-EpitheUal Tissues 93 



Muscular Tissue 93 



Nervous Tissue 96 



Tissues Serving for Mechanical Support 100 



Adipose Tissue 106 



Blood 106 



Histological Specificity 108 



4. The Integumentary System 1 1 1 



Evolution of the Skin m 



Structure of the Human Skin 113 



vii 



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