24 ELEMENTARY TREATISE ON STOCK FEEDS AND FEEDING 



be used for reproducing the plant. The leaves or growing parts, 

 are rich in protein while the shucks, which protect the grain, are 

 low in nitrogenous substances. The distribution of protein in 

 corn is similar to the distribution of protein in other plants. 



Protein in Animals. — Protein in animals is present as album- 

 inoids, gelatinoids, and as horny substances. 



Albuminoids are found in all the healthy organs and fluids of 

 the animal body except the urine. The principal albuminoids 

 are the albumen, such as white of egg, which is found in most 

 animal fluids, the casein of milk, the fibrin of meat, and the 

 fibrin of blood (present in the clotting of blood). 



Gelatinoids. — The nitrogenous substances of bone and cartilage 

 are gelatinoids. We have all no doubt noticed in the cooking 

 of bones and tendons, the familiar substance gelatine which is 

 derived from the gelatinoids perhaps by taking on water. The 

 connective tissue, ligaments and the skin contain gelatinoids. 



Horny Substances. — The protein in the hair, horns, hoofs, wool, 

 etc. is somewhat similar to the albuminoids and gelatinoids. 

 Per Cent. Protein in Animai, Bodies.* 



Thin animals contain more protein than fat animals because 

 the protein is present in lean meat in greater proportions than in 

 fatty tissues. 



There is a greater per cent, of protein in the animal body than 

 in most plants or parts of plants. 



Suggestion: Chop up some meat and extract it with cold 

 water. Boil the extract and note the albumin that separates out. 

 Treat this albumin with cold water again and see if it is soluble. 

 Have the students state whether it is better to soak meat in cold 



1 Lawcs and Gilbert, Bui. 2or, Ohio Experiment Station. 



