9$ THE OHEMISTR? OF THE 



The digestibility of the foods in the upper division 

 of the table has been for the most part determined by 

 feeding the animals on these foods alone; the digesti- 

 bility of the foods in 'the lower division of the table, 

 and also of roots, has been found by supplying these 

 foods in various proportions along with hay, the digesti- 

 bility of which had been already ascertained with the 

 same animal. 



In the case of ordinary meadow and clover hay 

 the total organic matter digested is but 55 to 60 per 

 cent, of that supplied ; with hay of exceptional quality 

 the proportion digested may rise to 70 per cent. With 

 straw only 45 to 50 per cent, of the organic matter is 

 generally digested, the minimum occurring with wheat 

 straw. 



The digestibility of the nitrogenous matter in hay and 

 straw appears to increase as its proportion rises. A 

 sample of wheat straw experimented with contained 

 4*8 per cent, of nitrogenous matter in its dry substance, 

 of which only one-fifth, or 20 per cent., was digested ; 

 while good lucerne hay with 19*3 per cent, of nitrogenous 

 matter had 76 per cent, of this in a digestible form. 

 The precise nature of the digested and undigested nitro- 

 genous matter has not yet been ascertained ; amides being 

 soluble bodies have undoubtedly been usually reckoned as 

 digestible albumin. 



Of the fibre in hay and straw about 40 to 60 per cent. 

 is generally digested by ruminant animals. The fibre of 

 leguminous hay and straw (clover and lucerne hay, and 

 bean straw) is less digestible than the fibre of similar 

 graminaceous foods (grass hay, oat and wheat straw). It 



