116 Cattle Problems. 



tivity ; while more blood is made by the grade, because it 

 acquires more muscle, and thereby more power to digest 

 food and form blood. But improvement so acquired can 

 be only quite transient, because it does not rest on any 

 basis really pertaining to, or developed by, the breed re- 

 ceiving the infusion of blood. 



There are several sources of breeding power in aux- 

 iliary degrees, but the main source of successful breed- 

 ing power in the degree that is necessary to perpetuate a 

 race or breed of cattle z^^impaired, consists in plenty of 

 vital blood; by vital blood being meant that quality which 

 contains a natural proportion of oxygen, about half the 

 mass of the blood being composed of crude, unassimilable 

 matter; which, however, serves, by its distensive bulk, to 

 keep the blood-vessels of their proper size. 



The gross bulk of the blood before it goes to the lungs, 

 is 7toi vitalized or complete, as blood ; for it quickly ceases 

 to flow or to nourish the tissues unless it contain vital air 

 or oxygen; but after it receives the necessary proportion 

 of oxygen, mixed with 45 per cent of its bulk, the blood 

 is vitalized, or completed in its elements, and therefore 

 circulates and nourishes the tissues. The crude blood is 

 not capable of sustaining life, but after it has passed through 

 the lungs nearly half the bulk of the blood becomes nutri- 

 tive from its acquisition of oxygen. Hence it is breath- 

 ing /hat makes the blood vital or capable of sustaining life. 



Oxygen is the principal agent in the renewal of the vital 

 structure in all parts which receive blood, and its constant 

 use for this renewal, and to remove dead or worn matter, 

 is the reason that blood divested of oxygen will not circulate. 

 So the circulation of the blood, in mass, is due to its life- 

 giving oxygen ; and even the fine fibres of muscle die 

 when divested of this vital element. Crude blood maybe 

 formed in large bulk by large cattle, and may contain 

 the other necessary ingredients, as albumen, phosphate, etc.; 



