CHAPTER II 

 REPRODUCTION 



THE value of a breeding animal is measured by its 

 own individual character, its ability to transmit desir- 

 able characters to its offspring, and by its prolificacy. Of 

 two animals of equal individuality and inheritance, the 

 one capable of producing numerous and vigorous offspring 

 will be the more valuable. The subject of reproduction 

 in animal-breeding is therefore of great importance and 

 second only to inheritance in estimating animal values. 



Two methods of reproduction are common among 

 plants and animals, asexual and sexual. These differ 

 greatly in form and method but accomplish the same 

 ultimate result, which is the continuance of the race. 



17. Asexual reproduction. The asexual method of 

 reproduction is common among the simplest forms of 

 plant and animal life. It is a process of cell division 

 or fission which varies in different forms, but in its most 

 elementary manifestations it is simple cell division. In 

 unicellular forms the cytoplasm of the cell and the nucleus 

 divide into two equal parts and each half becomes a 

 perfect new individual. Each new cell increases in bulk 

 by the absorption of food and in turn becomes a parent 

 cell and reproduces by division as before. A similar 

 form of reproduction is found in the developing embryo 

 of mammals and of the other body-cells. The tissues of 



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