HEREDITY AND HUMAN IMPROVEMENT 373 



on its arm, resembling a mouse. In another case a 

 dentist raised up the lip of a lady to look at an eye tooth. 

 Her child born shortly afterward had a hare lip or lip 

 cleft at one side like that of a hare. The first case was 

 probably a coincidence and the second cannot have been 

 due to the alleged cause because hare lip, a phenomenon 

 occurring in lower animals as well as in man, is due to 

 lack of junction of two embryonic rudiments and is caused 

 very much earlier in development than the period in 

 question. The connection between mother and child is 

 established through the organs of circulation and while 

 anything such as sickness, starvation or alcohol which 

 deteriorates or poisons the blood of the mother may be 

 very unfavorable to the child there is no good evidence that 

 the mother's imagination can paint pictures on the child's 

 body, or bring about specific deformities. Most of the 

 latter which are attributed to maternal impressions, 

 occur also in the lower animals and are well known to 

 pathologists as due to quite different causes. 



Heredity is fast coming to be the subject matter of an 

 exact science. This is largely due to the discovery of a 

 remarkable law which is named after its discoverer, 

 Gregor Mendel, an Austrian monk. For years Mendel 

 had been experimenting by crossing varieties of sweet 

 peas and other flowers; he finally published his results in a 

 rather obscure periodical where his papers remained 

 unnoticed until the year 1900 when they were brought to 

 light. The rediscovery of Mendel's law in 1900 made an 

 epoch in the study of heredity, for those who have followed 

 in Mendel's footsteps, verifying and extending the inves- 

 tigations which he began, have shown that Mendel's 

 long forgotten law affords the key that unlocks many 

 mysteries previously obscure and makes it possible to 



