130 THE DOMESTIC SHEEP 



as the .horns do not add one cent to the value of an animal, 

 and has really so many pounds of matter in them that 

 might, if turned that way, add so much to the weight of the 

 fleece, it follows that the shepherd may ask himself this 

 pertinent question, Why waste food in the making of a pair 

 of seven or eight pound horns, instead of breeding off 

 these horns and making more wool of the food and nutri- 

 ment so used to waste? 



But this is only one part of the subject of the natural 

 necessities of the animal. Food supports life, as well as 

 growth. Life is the first to be considered. And the support 

 of this calls for a large quantity of nutriment. It may be 

 said that life is supported by heat. The process of breath- 

 ing, by which the blood ic purified by every breath drawn, 

 is a chemical operation which is well worth study. As the 

 blood circulates through the system it takes up a largo 

 quantity of waste matter, the product of the muscular move- 

 ment of the animal, and the action of every vital organ. 

 The bright red, pure blood, which is forced by the muscular 

 action of the heart through the arteries, by which it is car- 

 ried to the capillaries or minute veins just under, and all 

 through the skin; and these are so exceedingly fine, and are 

 so closely placed in a dense network that the point of the 

 finest needle cannot penetrate the skin, anywhere, with- 

 out wounding one or more of them and drawing 

 blood; this blood thus passing through these minute 

 veins supply every part of the body with the nutri- 

 ment that is derived from the food, and at the 

 same time wash, as it were, away all the impurities caused 

 by the constant action of the muscles, and then changing 

 from the bright crimson of the arterial blood, to a dark, al- 

 most black, color, returns to the heart, by whose pulsation- 

 like that of a pump this dark blood is forced into the lungs 

 where it is acted upon by the oxygen of the air breathed. 

 This oxygen consumes these impurities. Some of them are 

 excreted by the skin in the form of perspiration, which is 

 always going on, whether in heat or cold, but mostly un- 

 der the influence of heat. This consumption of this impure 

 matter by the oxygen of the air breathed into the lungs, is 

 equivalent to a burning up of these impurities mostly con- 

 sisting of carbonaceous matters, and by this burning, heat 



