CHAPTER Vile 
THE TRANSMISSION OF MALFORMATIONS AND ACQUIRED 
DEFECTS. 
IN this chapter it is not proposed to discuss in all its 
bearings the question of heredity, or even to propose a 
theory to account for the transmission of defects from 
parents to offspring. At the present day such an under- 
taking is rendered unnecessary, for all thinking persons 
are unanimous in believing that malformations of de- 
velopment, as well as the tendency to certain diseases, 
are inherited, or, as it is familiarly expressed, “run in 
families.” If anything, perhaps there is a disposition to. 
ascribe too much to inheritance instead of submitting 
suspected cases to critical analysis. My object on the 
present occasion is to criticize a few examples of sup- 
posed instances of the transmission of characters the 
result of mutilation. 
I shall commence with an easily observed part of a 
mammal’s body—the ear, or pinna. In the chapter on 
Environment it was pointed out that good evidence 
leads us to believe that it is justifiable to regard the 
pinna as an enlarged operculum, modified for acoustic 
purposes in terrestrial mammals. Before discussing the 
malformations of the external ear we may profitably 
consider some facts connected with its anatomy. 
— : 
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