692 THE POPULAR SCIENCE MONTHLY. 



no reason to doubt that genius is hereditary, though, from the obvious 

 conditions of the case, it is rarely transmitted in like quality and de- 

 gree from parent to child. The subject is too large to be advan- 

 tageously considered here ; but those interested in it will find a vast 

 mass of striking information and ingenious reasoning in Mr. Francis 

 Galton's admirable work on " Hereditary Genius." 



A case is on record of a man who possessed the habit of sleeping 

 on his back with the right leg crossed over the left. His daughter, 

 while still an infant in the cradle, exhibited the same peculiarity. The 

 possibility of imitation, conscious or unconscious, is here obviously 

 excluded. A case has been reported to the writer of a man who had 

 the habit of alternately flexing and extending his great toe while lying 

 in bed. His grandson developed the same habit, though quite igno- 

 rant of his grandfather's peculiarity. Ribot records a curious in- 

 stance of a domestic servant who exhibited an incurable vice of 

 loquacity. She talked incessantly to any one who would listen, to 

 animals, to inanimate objects, and even to herself. When upbraided 

 Math her folly, she said it was not her fault, as her father had possessed 

 just the same habit, and had almost driven her mother distracted 

 by it! 



Instinct is strongly hereditary in animals, even under the most un- 

 favorable conditions. Ducklings hatched by a hen take to water im- 

 mediately on breaking their shell ; and every one is familiar with the 

 spectacle of the distracted mother wildly running to and fro on the 

 margin of the duck-pond, while her youthful family, heedless of her 

 terror, disport themselves delightedly upon its surface. If the eggs of 

 the wild duck be placed under one of the domesticated species, the 

 young, when their feathers are complete, immediately take to the 

 wing. Birds hatched in confinement construct in their cages the same 

 kind of nest as their more fortunate brethren of the same species build 

 in the virgin forest. Many curious and apparently mysterious facts are 

 explicable on the hypothesis of the permanence under changed con- 

 ditions of traces of aboriginal instincts. Thus, the domesticated dog, 

 even when thoroughly well cared for, is very fond of burying a bone 

 in some secret spot — a lingering trace, probably, of the time when he 

 ran wild in the woods, and the secreting of surplus food for a future 

 occasion was a matter of practical importance to him. When the 

 squirrel is reared in confinement, it stores away in a corner of its cage 

 a portion of the nuts supplied to it, an instinctive preparation for the 

 coming winter, unnecessary, indeed, for this individual squirrel, but 

 highly important for its ancestors and congeners living in the wild 

 state. Every one must have observed how difficult it is to make the 

 common ass leap over a stream, however small. This unwillingness 

 is not the result of an inherent incapacity for jumping, as the ass 

 leaps over other'obstacles with ease, while it hesitates obstinately at 

 the tiniest streamlet. We have here, in all probability, a remnant of 



