10 THE DOG IN HEALTH. 



is the modification that his nature undergoes in relation 

 to the climate and modes of life of the peoples among 

 whom a particular breed happens to be developed. 



English dogs, especially of some breeds, like English- 

 men themselves, fail to adapt readily to certain climates, 

 as those of India and Africa. 



In order to understand the dog, either in health or 

 disease, it is indispensable to know something of the way 

 in which animals live, move, and have their being in oth- 

 er words, the conditions of animal existence. From time 

 to time this subject will be referred to in detail as it con- 

 cerns the dog. In the mean time the following brief out- 

 line * may serve a good purpose, alike for those who have 

 and those who have not studied physiology as a science : 



The Animal Body. An animal may be made up of a 

 single cell in which each part performs much the same 

 work ; or, if there be differences in function, they are ill- 

 defined as compared with those of higher animals. The 

 condition of things in such an animal (as Amoeba) may be 

 compared to a civilized community in a very crude social 

 condition. When each individual tries 'to perform every 

 office for himself, he is at once carpenter, blacksmith, 

 shoemaker, and much more, with the natural result that 

 he is not efficient in any one direction. A community 

 may be judged in regard to its degree of advancement by 

 the amount of division of labor existing within it. Thus 

 is it with the animal body. 



Looking to the existing state of things in the universe, 

 it is plain that an animal to attain to high ends must have 



* Taken, with some modifications, from the author's Comparative 

 Physiology. D. Appleton & Co., New York, 1890. 



