CHAPTEK IY. 



HEREDITY OF ACQUIRED AND ABNORMAL CHARACTERS. 



THE habits and characteristics of animals that have 

 been developed by the conditions in which they are 

 placed, or the peculiar training they have received at 

 the hands of man, appear to be transmitted from gen- 

 eration to generation, with nearly the same certainty 

 and uniformity as those that characterize the original 

 type or species from which they are descended. 



Some of the most striking illustrations of this form 

 of heredity are to be found in the transmission of the 

 highly-artificial peculiarities that characterize the vari- 

 ous improved breeds of animals. The tendency to 

 lay on fat rapidly and to mature early is inherited in 

 the best families of the Short-horns the Devons, the 

 Herefords, and other meat-producing breeds while 

 the ability to secrete an abundant supply of milk is, 

 in like manner, perpetuated in the Ayrshires, the Jer- 

 seys, and other dairy breeds. 



The certainty with which these acquired qualities 

 are transmitted constitutes one of the most valuable 

 peculiarities of a breed. 



The American trotting -horse furnishes another 

 illustration of the inheritance of acquired characters. 



The various breeds of dogs have peculiarities that 



