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Care and Nourisnment of tne Developing Young 



A. Introduction 



1. Care in relation to the number of young produced 



2. General environmental conditions necessary for development 



3. Types of enveloping or protective membranes 



4. Types of food sources 



5. Mechanisms for oxygen supply and carbon dioxide removal 



6. Oviparity, ovoviviparity, and viviparity 



B. Formation and importance of the protective embryonic membranes 



1. The egg membranes 



a. Primary and secondary egg membranes 



b. Tertiary egg membranes 



1) Mammals 



2) Birds 



a) Formation of the chalaziferous layer 



b) Deposition of the middle dense layer of albumen 



c) Formation of the inner liquid layer of albuminous material and the 

 chalazae 



d) Deposition of the outer liquid albuminous layer 



e) Formation of the egg membranes and egg shell 



3) Reptiles 



4) Amphibians 



5) Fishes 



2. The extra-embryonic membranes 



a. Yolk sac 



b. Amnion 



c. Chorion (serosa) 



d. Allantois 



e. Yolk stalk, allantoic stalk, belly stalk, and umbilical cord 



3. The reproductive duct as a protective embryonic membrane 



4. Uncommon or specialized structures as protective mechanisms 



C. Special adaptations of the extra-embryonic membranes for uterine existence 



1. Implantation 



a. Definition 



b. Types of implantation 



2. The placenta and placentation 



a. Definition 



b. Types of embryonic tissues involved in placentation 



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