S 3 THE POPULAR SCIENCE MONTHLY. 



with the right leg crossed on the left. One of his daughters had the 

 same habit from birth ; she constantly assumed that position in the 

 cradle, notwithstanding the resistance offered by the swaddling-bands. 

 The same author assures us that he has oftentimes noticed in children 

 other habits no less extraordinary, which they must have received 

 from their parents, and which cannot be attributed either to imitation 

 or to education. Darwin gives another instance : A child had the 

 odd habit of setting its fingers in rapid motion whenever it was par- 

 ticularly pleased with any thing. When greatly excited, the same 

 child would raise the hands on both sides as high as the eyes, with the 

 fingers in rapid motion, as before. Even in old age he experienced a 

 difficulty in refraining from these gestures. He had eight children, 

 one of whom, a little girl, when four years of age, used to set her lin- 

 gers going and to lift up her hands after the manner of her father. 

 Finally, heredity has been observed in handwriting. There are fami- 

 lies in which the special use of the left hand is hereditary. Various 

 peculiarities of sensorial conditions are transmitted in a similar way. 

 Nearly all the members of the Montmorency family were affected with 

 an incomplete strabismus, which used to be called the Montmorency 

 look. The incapacity to distinguish between different colors is no- 

 toriously hereditary. The distinguished English chemist, Dalton, and 

 two of his brothers, were thus affected, and hence the affection itself 

 received the name of Daltonism. Deafness and blindness are some- 

 times hereditary, though not often, and deaf-muteness still more rare- 

 ly. Some curious instances are given of the transmission of certain 

 perverse tastes. Lucas, according to Zimmermann, relates the follow- 

 ing : A man in Scotland was possessed of an irresistible desire of eat- 

 ing human flesh. He had a daughter. Although removed away from 

 her father and mother, who were sent to the stake before she was one 

 year old, and although brought up among respectable people, this girl, 

 like her father, succumbed before her strange craving for human flesh. 

 This is clearly a case allied to insanity. 



Insanity is, beyond all doubt, transmitted by heredity. Among 

 1,375 lunatics Esquirol found 337 cases of hereditary transmission. 

 Guislain and other physicians, on a rough estimate, represent the pa- 

 tients affected with hereditary insanity as one-fourth of the total num- 

 ber of the insane. Moreau, of Tours, and others, hold that the propor- 

 tion of the former is still greater. The heredity of insanity does not 

 imply merely direct transmission of insanity (alienation), properly so 

 called; hysteria, epilepsy, chorea, idiocy, hypochondria, may result 

 from insanity, and, vice versa, they may produce insanity. In passing 

 from one generation to another, these various neuroses (nervous affec- 

 tions) are in some way transformed into one another. 1 Herpin, of Ge- 



1 Simple alcoholic intoxication may pass into profound neuroses. Children conceived 

 during an acute attack of intoxication are often epileptic, insane, idiots, etc. These facts 

 were observed long ago. A law of Carthage forbade all beverages except water on the 



