21 



Tne Developing Endocrine Glands and Tneir Possime 



Relation to Definitive Body Formation and tne 



Dirrerentiation or Sex 



A. Introduction 



B. Morphological features and embryological origin of the endocrine glands 



1. Pancreas 



2. Pituitary gland (hypophysis cerebri) 



a. Anterior lobe 



b. Posterior lobe 



c. Pars intermedia 



3. Thyroid gland 



4. Parathyroid glands 



5. Thymus gland 



6. Pineal body 



7. Adrenal (suprarenal) glands 



8. Gonads 



C. Possible influence of endocrine secretions on the development of definitive body form 



1. Thyroid and pituitary glands and anuran metamorphosis 



2. Thyroid and pituitary glands in relation to the development of other vertebrate 

 embryos 



a. Chick 



1) Thyroid gland 



2) Pituitary gland 



b. Mammal 



1) Thyroid gland 



2) Pituitary gland 



c. Fishes 



3. General conclusions relative to the influence of the thyroid and pituitary glands 

 in vertebrate embryology 



D. Possible correlation of the endocrine glands with sex differentiation 



1. Differentiation of sex 



a. General sex features in the animal kingdom 



b. Chromosomal, sex-determining mechanisms 



c. Possible influence of the sex field in sex determination 



2. Influence of hormones on the differentiation of sex 



3. General summary of the factors involved in sex differentiation in the vertebrate 

 group 



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