lii INTRODUCTION. 



that he can scarcely be identified with the Brown Bear of 

 the Norwegian Alps. In these and other cases, the changes 

 produced furnish continual matter of debate to zoologists, 

 whether the animals are to be regarded as distinct species, 

 or as varieties of the same species. 



The changes produced on animals in a state of nature by 

 different circumstances, as the nature of the country they 

 inhabit, the means of obtaining their food, temperature, 

 and altitude, are often very great ; but it is when they are 

 reduced to the domesticated state, that all the changes which 

 they are capable of undergoing are manifested in the great- 

 est degree. Sometimes, as in the case of the Dog, it would 

 seem as if the influence of human reason worked a charm 

 upon their nature, nay, modified the form of their bodies, as 

 if to suit them for new services. Sometimes by the mere 

 supply of aliment, different in kind from that which they 

 procure in the natural state, or in greater quantity, the 

 form of the body changes, and with this their instincts and 

 habits ; and further, this change in their conformation is 

 capable, under certain limits, of being transmitted to their 

 descendants, and, by continued reproduction, of producing a 

 new breed, variety, or race. 



The Wild Hog, which extends over the greater part of the 

 Old Continent, is the undoubted progenitor of the common 

 domesticated races of Europe. When this powerful and soli- 

 tary creature is subjected to domestication, we shall find, in 

 the sequel, that not only his form, but all his habits change. 

 He may be said, in fact, to become a new species ; and he 

 transmits all his acquired characters to his descendants. The 

 parts of his conformation regarded as the most constant in 

 the discrimination, not only of species but of genera, change 

 under the new relations in which he is placed. In the 

 wild state, he has six incisor teeth in the upper, and six in 

 the lower jaw ; but, under the effect of domestication, the 

 number is generally reduced to three in each jaw. The num- 

 ber of his dorsal, lumbar, sacral, and caudal vertebrae, vary 



