HEREDITY. 431 



vous diseases acquired by parents through environ- 

 ment have been transmitted in some shape to children, 

 but this evidence is not nearly so conclusive as the ex- 

 perimental proof cited. 



1 ' In conclusion we may say that the drift of all the 

 collated observations on both man and brute seem to 

 indicate that certain of the changes produced in the 

 animal body by disease are often to some degree trans- 

 mitted, that these may be cumulative and lead to de- 

 generation if not indeed to the extinction of families. 

 The experience of breeders as well as the observations 

 of medical men practically establishes the fact that ac- 

 quired weakness and defects occurring in successive 

 generations may result in truly hereditary unsound- 

 ness." 



d. Inheritance of Characters Due to Mutilation and 

 Injuries. 



While characters of this kind are relatively rarely 

 inherited, there is little doubt that they can be. Dr. 

 Brewer cites a few cases for illustration ; ' some of 

 them have been already published, others have not. 

 They are not the most striking, but are chosen because 

 they are representative. 



"a. A mare in foal had an eye seriously injured by 

 burdocks entangled in the forelock. She suffered with 

 violent ophthalmia, and in due time dropped a foal (a 

 filly) which had the corresponding eye aborted. She 

 afterwards bore several normal foals. 



"(This case came under the observation of the 

 eminent veterinarian, Professor Law of Cornell Uni- 

 versity. Papers American Public Health Association, 

 2, p. 254.) 



"&. A game-cock, in his second year, lost an eye 



