Numerous instances are on record tending to show that even accidents do sometimes, although not usually, become hereditary. Blumenbach mentions the case of a man whose little finger was crushed and twisted by an accident to his right hand. His sons inherited right hands with the little finger distorted. A bitch had her hinder parts paralyzed for some days by a blow. Six of her seven pups were deformed, or so weak in their hinder parts that they were drowned as useless. A pregnant cat got her tail injured; in each of her five kittens the tail was distorted, and had an enlargement or knob near the end of each. Horses marked during successive generations with red-hot irons in the same place, transmit visible traces of such marks to their colts.
Very curious are the facts which go to show that acquired habits sometimes become hereditary. Pritchard, in his "Natural History of Man," says that the horses bred on the table lands of the Cordilleras "are carefully taught a peculiar pace which is a sort of running amble;" that after a few generations this pace becomes a natural one; young untrained horses adopting it without compulsion. But a still more curious fact is, that if these domesticated stallions breed with mares of the wild herd, which abound in the surrounding plains, they "become the sires of a race in which the ambling pace is natural and requires no teaching."
Mr. T.A. Knight, in a paper read before the Royal Society, says, "the hereditary propensities of the offspring of Norwegian ponies, whether full or half-bred, are very singular. Their ancestors have been in the habit of _obeying the voice_ of their riders and _not the bridle_; and horse-breakers complain that it is impossible to produce this last habit in the young colts. They are, however, exceedingly docile and obedient when they understand the commands of their masters."
A late writer in one of the foreign journals, says that he had a "pup taken from its mother at six weeks old, who although never taught to 'beg' (an accomplishment his mother had been taught) spontaneously took to begging for every thing he wanted when about seven or eight months old; he would beg for food, beg to be let out of the room, and one day was found opposite a rabbit hutch apparently begging the rabbits to come and play."