130 Breeding Plants and Animals. 



leading feeding experimenters on a tour of inspection 

 of the hogs in a national show. When asked if breeding 

 would not be a better and more economical way to in- 

 crease the percentage of lean meat on the carcass than 

 by special feeding he replied practically as follows : 

 "Nature gives us the proportions of bone, lean and fat. 

 All we can do is to add a little to the lean by giving a 

 ration -especially rich in protein," The fallacy of this 

 reasoning has been disproved to my satisfaction by in- 

 spection of numerous hogs slaughtered by myself and 

 by my present associate and former assistant Prof. An- 

 drew Boss. The first two hogs slaughtered a dozen 

 years ago in the instructional work of slaughtering and 

 handling meat in the Minnesota School of Agriculture 

 opened up to the writer a large field of study. These 

 two young hogs were equal in age and had been raised 

 together. One was a Small Yorkshire, the other a Po- 

 land-China-Duroc-Jersey hybrid. It is worthy of note 

 that the word "hybrid" is coming into use wherever 

 distinct types of plants are crossed, and as it has proved 

 preferable there should also be used in animal breed- 

 ing, the principles in this respect being quite similar 

 in plant and animal-breeding. The Small Yorkshire 

 carcass had muscles outside the bony 'framework, the 

 thickness of which we may represent by one inch, 

 while the outside fat was two inches thick. The other 

 hog had a much larger frame, but the percentage of 

 lean meat was much larger in proportion to skeleton, 

 dressed carcass or to live weight than in the Small 

 Yorkshire carcass, and its proportions could almost 

 Be stated in reverse order, as lean meat two inches thick 

 and the fat covering one inch thick. Prof. Boss has 

 numerous photographs of cross-sections of hog car- 

 casses, showing larger and smaller percentages of lean 

 meat. These differences occur not only between ani- 

 mals of different breeds,, but among those of one breed 

 and even among those of one litter. And the variation 

 is not slight; it is often marked, just as there are 

 marked differences in the yields of wheat plants of the 



