Breeds of Sheep test adapted to different Localities. 451 



wise have been consumed in the lungfs and exhaled in the form 

 of carbonic acid, becomes deposited in the cellular tissue as a 

 hydro-carbon — fat. 



With the hardier active breeds of sheep, such as the South- 

 down, Ryeland, Black-faced, Herdwick, &c., the lungs are more 

 largely developed in consequence of the additional exercise which 

 they are compelled to take in order to obtain a sufficient amount 

 of nutriment; on the dry downs being deficient in quantity, whilst 

 on the heathy mountains it is deficient in quality — either or both 

 causes will necessarily compel the sheep occupying such pastures 

 to make increased exertions to satisfy their appetites, beyond what 

 would have been required from them were they grazing on a 

 luxuriant plain; thus a development of lung and corresponding 

 activity of disposition become concomitant physiological features 

 of the respective breeds. From this cause arises the fact that 

 the old down and black-faced sheep will not fatten until they 

 have passed the third year, for which the following reason may be 

 assigned : in the earlier stages of life the circulation of the blood 

 is much quicker than at a maturer period, being the most rapid 

 in infancy, and the slowest in old age. This is one of the most 

 beautiful provisions of nature, as by this means the warmth ne- 

 cessary during youth and infancy is secured ; every extra pulsation 

 which drives the venous blood through the lungs in order to be- 

 come again oxygenated is attendant with the formation of carbonic 

 acid gas, evolved in the act of respiring, heat at the same time 

 being developed. As the animal becomes older, the circulation 

 ceasing to have the same rapidity, consequently consumes less of 

 the carbonaceous matter in the food, the difference being, as in 

 the former instance, converted into fat : a large development of 

 lung is therefore inseparably connected with a breed which is con- 

 stantly exposed to the effects of cold, as on a bleak down, in order to 

 maintain the requisite animal heat ; this scantiness of herbage 

 enforces on the animal increased exercise. Large lungs and 

 great exertion are both adverse to the formation of fat. It is 

 therefore clearly impossible to obtain a breed of sheep which 

 will withstand the effects of cold and scanty herbage, and at the 

 same time possess the valuable property of arriving at early ma- 

 turity. All the breeds which are of a hardy nature possess deep, 

 but not wide chests, such are the black-faced, the Herdwick, 

 the old-horned Wiltshire, the old Southdown, the Welsh, &c., 

 and all require to have passed their third year before they will 

 put on fat profitably. The Cheviots and the Cotswolds hold 

 an intermediate position between the Leicesters and the more 

 hardy races, not possessing the early fattening property of the 

 former, nor quite so hardy as the latter ; in this respect it will be 

 found that their position is fixed in a great degree by the character 



