292 Disease among Lambs. 



of sheep possessing a disposition to accumulate fat, the early 

 arrival at maturity is increased, and the animals are earlier ready 

 for the market; but all this takes place at the expense of robust 

 health, and the improved breeds are far more susceptible to the 

 effects of inclement weather and deficiency of a proper supply of 

 food. I am of opinion that in sheep of such improved breeds 

 the disposition to accumulate fat is evinced before the animals 

 arrive at maturity, and a diminution of the nutritive organs takes 

 place before the tissues are thoroughly developed. It is necessary 

 for the proper nutrition of the muscular structures, especially 

 during their development, that they should be subjected to exer- 

 tion ; but the improved breeds of sheep, whose temperament is 

 sluggish, are inactive and averse to motion, and their tissues do 

 not attain that degree of firmness which is characteristic of robust 

 health. 



I also conclude that the herbage indigenous to the fertile 

 pastures of Lincolnshire and Leicestershire is richer in flesh- 

 forming substances than that upon the cold and comparatively 

 poor land of Derbyshire, and the sheep, therefore, are necessitated 

 to endeavour to attain the natural standard of their race upon 

 food which, considering their powers of assimilation, is not rich 

 enough in nitrogenous matter to enable the blood to meet the 

 demands of the system. 



The occurrence of the disease in the autumn of the year is also 

 an argument in favour of my theory. Dry summer weather is 

 very unfavourable to the fresh growth of herbage, and animals at 

 pasture are obliged to eat old dry innutritious grass from hedge- 

 rows or any other places where they can find it, after cropping 

 the small amount of fresh nutriment afforded by their scanty 

 pastures ; their supply of flesh-forming materials is thus again 

 decreased. I have the authority of Boussingault and Voelcker 

 for stating, that when vegetables have matured their seeds the 

 nitrogen they contain is diminished, and when they are dried it 

 is reduced to its minimum. Since the outbreak of the disease 

 quickly follows upon abundant rains and genial weather, or upon 

 the removal to turnips, we are led further to infer that the blood, 

 already attenuated by containing a small amount of fibrin and 

 albumen, on being further diluted by the introduction of a large 

 quantity of moisture taken up in quickly-grown succulent herbage 

 and roots, becomes of too small specific gravity, and the elimina- 

 tion of the superabundant water by the mucous membrane of the 

 alimentary canal is one of nature's efforts to restore the vital fluid 

 to a normal consistency. 



As regards the general management of the flock, it is well 

 known that imperfect nourishment quickly embarrasses the diges- 

 tive functions, producing loss of tone in those organs. The object 



