42 MARRIAGE AND DISEASE. 



and the mental instability of the neurotic family been 

 developed by ages of habit. "Habit becomes second 

 nature" is an old saying which sums up what we have 

 been preaching, viz., that habit or, as Shakespeare 

 has it, use long continued is what builds up our 

 nature. Hamlet says : 



"Refrain to-night, 



And that shall lend a kind of easiness 

 To the next abstinence : the next more easy : 

 For use almost can change the stamp of nature." 



( Darwin says : " Characters of all kinds, whether 

 j old or new, tend to be inherited," and of the truth of 

 the statement there is proof everywhere around. The 

 transmission of acquired characters is well exemplified 

 in some of the inferior animals, as for example, the dog. 

 No one will assert that the sheep-dog, the retriever, 

 or the pointer is the result of an independent creative 

 act. We know that they are sprung from a common 

 stock, although they are now so widely separated 

 physically and mentally. Each one by a certain mode 

 of life has become modified from the original type. 

 The well-bred pointer, that is, one whose ancestors have 

 been trained to the same particular duties for many 

 generations back will ' point/ as we say, by instinct, 

 the young retriever retrieve to hand after a single 

 lesson, and the sheep-dog take to tending the flock 

 almost of his own accord. Those characters have 

 undoubtedly been acquired by the ancestors of the 

 puppies and been handed down from generation to 

 generation until they have become a part and parcel 



