20 SWINE 



lificacy. Consequently hogs that are selected for corn 

 belt conditions should have all of these points well de- 

 veloped. They should be large, rangy, strong in consti- 

 tution and vitality, and should be active and prolific. A 

 few generations of feeding may change a hog from one 

 type to the other, and a man who has not the ability to 

 mold a type according to his own ideals ought to select 

 hogs to begin with that are best adapted to the condi- 

 tions under which they are to be grown. 



COLOR OF SWINE. 



The color of the hog should have some consideration 

 in selecting a breed. As is quite generally known, the 

 black or dark-skinned hog is better able to withstand the 

 direct rays of the sun than is the white hog. In other 

 words, the white hog is more subject to sun-scald, blis- 

 ters, and consequently to skin diseases of various forms, 

 than the black hog. The reason for this apparently is that 

 the black cuticle of the black hog absorbs the rays coming 

 from the sun, whether they be heat rays, the light rays, or 

 the actinic (chemically active) rays, while the cuticle of 

 the white hog allows them to pass through. 



In order to develop a possible explanation for the above 

 mentioned fact, namely, that a white hog cannot with- 

 stand the direct rays of the sun as well as a black hog, it 

 is discussed from the standpoint of the heat rays. Never- 

 theless, the other rays may act in a similar manner. 



It is a well known fact that a black object lying in the 

 sun becomes hotter than an object of a lighter color. The 

 color of the hog is in the cuticle. This is also a well 

 known fact because all hogs, either black, red, or white, 

 are white after being dressed. The cuticle which carries 

 the pigment is taken off in such an operation. The cuticle 



