220 Medicine: 



follows that an otherwise perfect physical con- 

 stitution goes along with a perfect mental 

 constitution, or that you may not breed a mind 

 of extraordinary quality from a poor and lame 

 body. The owner of racehorses, basing his trust 

 on a law of heredity, no doubt does wisely to 

 give a thousand guineas for a yearling colt of a 

 distinguished sire, when he would not give a 

 thousand shillings for the offspring of a poor sire ; 

 but it would hardly be wise to buy the offspring 

 of a human genius at a like proportionate cost. 

 In the human organism, with its varieties of 

 changing moods and passions, there are delicate 

 influences, affecting gravely the processes of 

 reproduction, which invalidate conclusions drawn 

 from observation of the comparatively simple 

 organic machines which animals are ; for these 

 subtile-potent forces of mind probably constitute 

 a medium which acts powerfully on the formative 

 processes of the delicate germ ; not otherwise 

 than as, on a lower and coarser level, slight 

 experimental changes in the physical medium 

 are now experimentally shown to affect strangely 

 the development of the germs of sea-urchins, 

 caterpillars, and the like. 



Complex and uncertain as the matter is in the 

 human case, it is nevertheless certain that there 

 are laws of mental breeding yet to be discovered, 

 and it is no more unlawful to inquire scientifically 

 into the nature of vice and sin than into the 

 nature and actions of poisons. Hatred is as 



