MANUAL OF CATTLE- l^^EEDUSTG. 11 



piece of flesli, or of a mass of wood, was as really organ- 

 ized^ and formed as truly a part of it, as the so-called {?/'- 

 ganlc portion, but they are in common use with this 

 meaning. The organic matters of the animal body are 

 classiHed, according to whether they contain the element 

 nitrogen oi* not, as nitrogenous or non-nitrogenous. 



Fat. — Of the non-nitrogenous substances fat is by far 

 the most abundant. It is present in the blood in minute 

 quantities, generally constituting not more than 0.1 to 0.3 

 per cent, of it ; it exists in larger 

 quantity in the substance of the 

 nerv^es and in the bones, but is chief- 

 ly found enclosed in special cells or 

 tissues under the skin, on the kid- 

 neys, omentum, and mesentery, and 

 in the flesh between the bundles of 

 muscular fibres. -^q, t— (Sett^ast). iw- 



The thin membrane which com- *'®"^* 

 poses the cell-wall b of the fat-tissue is a nitrogenous sub- 

 stance, and constitutes only 0.8 per cent, of the whole 

 tissue when the latter is entirely filled with fat, but when 

 this is not the case its amount may rise to 4 per cent., or 

 over. 



The quantity of water in the fresh fat-tissue stands in a 

 fixed relation to the amount of membrane (about 5 or 6 to 

 1), so that the quantity of water may vary from 4 to over 24 

 per cent., according to whether the cells are more or less 

 laden with fat. 



Most of the fat-cells of the living body contain liquid, 

 perfectly transparent fat, but its consistency varies in the 

 difterent organs ; it solidifies to a solid, butter-like mass 

 more or less easily, according to whether the oily or the 

 solid fats predominate. The appearance, albo, as well as the 



