APPENDIX I 



Testosterone, the male hormone obtained directly from the 

 testis, has a double bond in the first ring : 



CH, 



oy 



TESTOSTERONE 



A large number of substances having androgenic potency, 

 and the steps by which they have been prepared synthetically, 

 are discussed by F. C. Koch in Sex and Internal Secretions. 

 Progesterone. The corpus luteum hormone can best be un- 

 derstood by comparison with its basic hydrocarbon, which is 

 called pregnane. This has the two methyl groups already seen 

 in androstane, and also an ethyl group (CH2 . CH3) as a side 

 chain on carbon 17. (The two ethylic carbons are numbered 

 20 and 21, those of the methyl groups being 18 and 19.) 



CH, 



CH2 



PREGNANE 

 { '^61 } 



