LAW OF SIMILARITY. 25 



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. Pritch- 

 ard, 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 sur- 

 rounding 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 Eoyal 

 Society, says, "the hereditary propensities of the oflF- 

 spring 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 bri- 

 dle ; and horse-breakers complain that it is impossible 



