78 HEREDITY IN RELATION TO EUGENICS 



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Fio. 45. — The central mating, II, 7, II, 8, is that of a man, II, 7, who is 

 subject to melancholia and has an insane brother and another who is neuro- 

 pathic. His wife is normal but her mother was neuropathic. The product of 

 this union is 11 children of whom 3 are neuropathic. One of these insane 

 children marries a normal person (probably of neuropathic ancestry), and has 

 2 neuropathic children besides 1 that is epileptic, IV, 1. E, epileptic; 

 /, insane; N, normal; shaded symbols imply some neuropathic condition other 

 than insanity. Cannon and Rosanoff, 1911. 



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Fig. 46. — The central mating is that of a normal man of neuropathic 

 stock with a neuropathic woman who has an insane sister. Since by hypothesis 

 all of her germ cells and half of his are "neuropathic" it is to be expected that 

 half of their offspring will be neuropathic in some degree. Actually, of 6 sur- 

 viving children 2 are epileptic, 2 highly nervous and 2 normal so far as 

 known. There is a slight, but not unreasonable deficiency of normals, 

 namely, 1. The shaded symbols represent nervous subjects. Cannon and 

 Rosanoff, 1911. 



children become insane. The typical laws of heredity are 

 followed here (Figs. 45-47). 



But is it so certain that alcoholic, traumatic, even syphil- 

 itic dementia have no hereditary basis? On the contrary 



