288 SCIENCE PROGRESS. 



the appropriate causes ; " that . . . the gouty diathesis, for 

 example, may be acquired by long habits of intemperance, 

 and transmitted to posterity," and so also with other ill 

 effects witnessed in the children of dissolute parents. If 

 this be so, Prichard admits that " we have a clear proof 

 of the hereditary nature of acquired states of the constitu- 

 tion ". 



Against such a view he contends that any particular 

 disease can only follow when there exists " a preparation, 

 laid in the first place by nature, in the original stamina and 

 habit of the body " ; and he points out that the same hurtful 

 cause may produce quite distinct diseases. Thus "intempe- 

 rate living ... is commonly said to bring on, in one person, 

 a predisposition to gout, in another to diseases of the liver, 

 or of the stomach, or of the brain. Now since the difference 

 is not in the external causes, it must be in the natural 

 peculiarities of the constitutions on which they act. These, 

 therefore, are previously fitted by original organization to 

 take on them one form of morbid affection rather than 

 another. It is then clear that the predisposition is laid by 

 natural or congenital structure, in the first instance." Indi- 

 viduals difter in particular organs ; the exciting causes of 

 disease bring out the weaknesses which previously existed 

 and mieht otherwise have remained unknown. Such de- 

 fects " being a part of the original bodily structure " are 

 hereditary. " The first individual who exposes himself to 

 the morbid causes, first betrays the peculiar defect of his 

 race, and is thus erroneously supposed to lay the foundation 

 for it." 



Syphilis, which appears to be an exception, he explains 

 by " a peculiar mode of infection. . . . This is evidently a 

 phoenomenon of a very different kind from the similarity of 

 structure which the laws of nature have ordained between 

 parents and their offspring." 



Hence he infers "that the phoenomena of predisposition 

 to diseases, rather confirms than invalidates the general 

 observations before laid down, and we may be allowed to 

 conclude, that no acquired varieties of constitution become 

 hereditary, or in any manner affect the race ". 



