320 THE CHEMISTRY OF ANIMAL PHYSIOLOGY 



Like starch in the plant, glycogen in the body is the concen- 

 trated, dehydrated form of storage carbohydrate material in 

 the animal. 



3. Lactose. — This is found in milk and will be described 

 in Section 244, a. 



4. Cellulose and Crude Fiber are not found in animals as in 

 plants. 



(b) Fats. — The fats are very much the same as in plants. 

 Their general properties are the same, but there are a few 

 animal fats and oils which deserve mention. 



1. Tallow is the name given to certain animal fats, more 

 or less hard in character and extracted or " rendered" from 

 adipose tissue by melting out the fat to free it from the 

 protein membranes. It is almost white when pure and nearly 

 tasteless. It is composed of mixed glycerides of stearic, 

 palmitic, and oleic acids in varying proportions, the com- 

 mercial grades usually containing free fatty acids due to 

 hydrolysis of the glycerides. Beef tallow or beef fat is 

 softer than mutton tallow. The former is used for making 

 oleomargarine (Section 248) and as an adulterant of lard 

 in addition to its use as a food. The latter is employed 

 in the making of soap, candles, and lubricants besides being 

 used as a food. 



2. Lard is the fat of pigs, and is obtained by rendering, 

 as in the case of tallow. It is composed of the glycerides of 

 stearic, palmitic, oleic, myristic, lauric, linoleic, and possibly 

 linolenic acids. 



3. Neatsfoot Oil is made from the feet and shin bones of 

 cattle by boiling in water. The oil rises to the surface and is 

 skimmed off. It is pale yellow in color, consisting chiefly 

 of olein with some palmitin and stearin. In leather dressing 

 and as a lubricant it finds its chief uses. 



4. Codliver Oil is extracted from the liver of the cod, pure 

 varieties being used in medicine, and other kinds in tanning. 

 Its composition is very complex, containing in addition to 

 myristic, palmitic, stearic, oleic, and erucic acids, two new acids. 



5. Menhaden Oil is obtained from the whole body of the 

 menhaden fish by boiling in water and expressing. It finds 

 various uses, as in soap making and tanning. 



