----------------------------+-----------------------------------------+ | Per cent. in Entire Animal. | Description +------+------+------+------+------+------+ of Animal. | A. | B. | C. | D. | F. | E. | ----------------------------+------+------+------+------+------+------+ Fat calf | 3·80 | 15·2 | 14·8 | 33·8 | 3·17 | 63·8 | Half-fat ox | 4·66 | 16·6 | 19·1 | 40·3 | 8·19 | 51·5 | Fat ox | 3·92 | 14·5 | 30·1 | 48·5 | 5·98 | 45·5 | Fat lamb | 2·94 | 12·3 | 28·5 | 43·7 | 8·54 | 47·8 | Store sheep | 3·16 | 14·8 | 18·7 | 36·7 | 6·00 | 57·3 | Half-fat old sheep | 3·17 | 14·0 | 23·5 | 40·7 | 9·05 | 50·2 | Fat sheep | 2·81 | 12·2 | 35·6 | 50·6 | 6·02 | 43·4 | Extra fat sheep | 2·90 | 10·9 | 45·8 | 59·6 | 5·18 | 35·2 | Store pig | 2·67 | 13·7 | 23·3 | 39·7 | 5·22 | 55·1 | Fat pig | 1·65 | 10·9 | 42·2 | 54·7 | 3·97 | 41·3 | ----------------------------+------+------+------+------+------+------+ Means of all | 3·17 | 13·5 | 28·2 | 44·9 | 6·13 | 49·0 | ----------------------------+------+------+------+------+------+------+ Means of 8 of the half-fat, | | | | | | | fat, and very fat animals | 3·23 | 13·3 | 29·9 | 46·4 | 6·26 | 47·3 | ----------------------------+------+------+------+------+------+------+ Means of 6 of the fat, | | | | | | | and very fat animals | 3·00 | 12·7 | 32·8 | 48·5 | 5·48 | 46·0 | ----------------------------+------+------+------+------+------+------+ SECTION III. USE OF FAT IN THE ANIMAL ECONOMY. As fat forms so large a portion of the body, it is evident that the part it plays in the animal economy must be a most important one. The general opinion which prevails amongst scientific men as to its physiological functions was originated by the celebrated Liebig. According to his theory, the food of animals includes two distinct kinds of substances--_plastic_[4] and _non-plastic_. The plastic materials are composed of carbon, hydrogen, oxygen, nitrogen, and a little sulphur and phosphorus. Albumen, fibrine, and casein are plastic elements of nutrition; they form the lean flesh, or muscles, the membranes, and cartilages, the gelatine of the bones, the skin, the hair, and, in short, every part of the body which contains nitrogen. The _non-plastic_ elements of nutrition include fat, oil, starch, sugar, gum, and certain constituents of fruits, such as pectine.