CARBOHYDRATES, ACIDS, FATS, OILS 81 



it is the intention to describe are often no more than half 

 fats or oils. The real value of the ether-extract from 

 different foods is partly determined, therefore, by its 

 source. When it is all oil, or nearly so, it is worth much 

 more for use by the animals than when it is made up to 

 quite an extent of other compounds. 



111. Fats or oils in grains and seeds. — The propor- 

 tions of fat or oil in cattle foods vary within wide limits. 

 In general, seeds and their by-products contain more than 

 the stem and leaves, the differences in the percentages of 

 actual oil being greater than is indicated by the ether- 

 extract. But little is found in the dry matter of roots 

 and tubers. Among the cereal grains and other more 

 common farm seeds, corn and oats show the largest 

 amoimts, the proportion in dry matter being from 5 to 6 

 per cent, while wheat, barley, rye, peas, and rice contain 

 much smaller percentages, wheat having about 2 per 

 cent, and rice sometimes not over one-fifth of 1 per cent. 

 Agricultural seeds that are especially oleaginous are 

 cottonseed, flaxseed, sunflower seeds, and the seeds of 

 many species belonging to the mustard family, such as 

 rape. Peanuts, coconuts, and palm nuts are also very 

 rich in oil. The average percentages in these seeds and 

 nuts are approximately as given below: 



Table XXIII. Oil in Certain Seeds 



The oils from all the above are important commercial 

 products, being used in a great variety of ways m human 



