BULLETIN 258. 



SOME COMMONLY NEGLECTED FACTORS UNDER- 

 LYLNG THE STOCK BREEDING INDUSTRY/ 



By Raymond Pearl. 



The Breedixg Industry. 



Animal-breeding as an industry lies at the foundation of 

 animal husbandry, which in turn is a basic element of the 

 art of agriculture. Before any of the domestic animals, can be 

 used to provide food or clothing for mankind, the animals 

 themselves must be produced. It is the function of the art or 

 craft of animal-breeding to produce the world's supply of 

 domestic animals of all kinds. 



An attribute of living organisms, which fundamentally 

 differentiates them from non-living matter, is the faculty of 

 self-reproduction. Certain cells of the body in all higher ani- 

 mals are able, under suitable conditions, to go through a process 

 of development which has as its end result the production of a 

 new individual of the race or species. Through these cells 

 (known as reproductive cells, or gametes) the animal has the 

 power of reproducing itself. A new and distinct individual 

 existence is brought into the world. Nothing like this is known 

 in the inorganic realm. The stone in the field is not capable, 

 through any self-initiated or self -perpetuated activity, of caus- 

 ing the coming into existence of a new stone, essentially like 

 itself in form, size, structure, chemical composition and every 

 other quality. Only plants and animals — in other words, living 

 things — can do this. 



'Papers from the Biological Laboratory of the Maine Agricultural 

 Experiment Station, Xo. 107. 



The substance of this paper was presented as an address before the 

 Maine Live Stock Breeders' Association at its meeting in Augusta, 

 December 5, igi6. The introductory portion is a reprint, with some 

 slight changes and corrections of typographical errors, of a paper 

 entitled "The Animal-Breeding Industry," published in the Scientific 

 Monthly, Jul}-, 1916, pp. 23-30. 



