GLOSSARIAL NOTE. 



The significations of the following words, habitually used by Dr. 

 Broca, are appended : 



AGENESIC. Mongrels of the first generation, entirely unfertile, 

 either between each other, or with the two parent species, and 

 consequently being unable to produce either direct descendants 

 or mongrels of the second generation. 



DYSGENESIC. Mongrels of the first generation, nearly altogether 

 sterile. 



a. Unfertile with each other, therefore with no direct de- 

 scendants. 



b. They sometimes, but rarely and with difficulty, breed with 

 one or the other parent species. The mongrels of the 

 second generation, produced by this interbreeding, are 

 infertile. 



PARAGENESIC. Mongrels of the first generation having a partial 

 fecundity. 



a. They are hardly fertile or infertile inter se, and when they 

 produce direct descendants, these have merely a decreasing 

 fertility, tending to necessary extinction at the end of some 

 generations. 



1). They breed easily with one at least of the two parent 

 species. The mongrels of the second generation, issued 

 from this second breeding, are themselves and their de- 

 sendants fertile inter se, and with the mongrels of the 

 first generation, with the nearest allied pure species, and 

 with the intermediate mongrels arising from these various 

 crossings. 

 EUGENESIC. Mongrels of the first generation entirely fertile. 



a. They are fertile inter se, and their direct descendants are 

 equally so. 



&. They breed easily and indiscriminately with the two 

 parent species ; the mongrels of the second generation, in 

 their turn are, themselves and their descendants, inde- 

 finitely fertile, both inter se or with the mongrels of all 

 kinds which result from the mixture of the two parent 

 species. 



