10 RELATIVE SIZE OF MALE AND FEMALE. 



vessels, — unless it is united with a spacious chest, 

 round ribs, large lungs, and a strong constitution. 



The more complete the correspondence between 

 these marks, the more the milking quality is connected 

 with the general condition of the animal, the greater 

 the chances of transmission ; and when, with a view to 

 breeding, we shall choose only animals having the two- 

 fold character of general vigor of constitution and 

 activity of the mammary system, and place the progeny 

 under favorable circumstances, the qualities will rarely 

 prove defective. Thus far the conclusions of Magne. 



Another well-known fact in natural history is, that 

 the size of animals depends very much upon the fer- 

 tility of the region they inhabit. Where food is abun- 

 dant and nutritious, they increase in size in proportion 

 to the quantity and quality ; and this size, under the 

 same circumstances, will run through generations, unless 

 interrupted by artificial means. So, if the food is 

 more difficult to obtain, and the pastures are short, the 

 pliancy of the animal organization is such that it 

 naturally becomes adapted to it, and the animal is of 

 smaller size ; and hence Mr. Cline observes that " the 

 general mistake in crossing has arisen from an attempt 

 to increase the size of a native race of animals, being a 

 fruitless effort to counteract the laws of nature." Mr. 

 Cline also says, in his treatise " On the Form of Ani- 

 mals : " " Experience has proved that crossing has only 

 succeeded in an eminent degree in those instances in 

 which the females were larger than the usual propor- 

 tion of females to males ; and that it has generally failed 

 when the males were disproportionally large. When 

 the male is much larger than the female, the offspring 

 is generally of an imperfect form ; if the female be 

 proportionally larger than the male, the offspring is 

 generally of an improved form. For instance, if a 



