NORTH-CAROLINA GEOLOGICAL SURVEY. 141 



flesh-forming. Milk contains these two classes probably in 

 the best proportions for young and growing animals. The 

 cheesey matter or curd is the flesh-forming and the butter or 

 oil the heat-generating. 



In all cases it is worthy of note, that water is a very large 

 constituent of bodies which are nutrient, even in lean meat 

 the highest form of flesh-forming matter, about four-fifths is 

 water. 



In vegetables, especially the seed, these two classes are 

 concentrated more than in the leaf or stem. The same bodies 

 exist in the stem and leaves, but in less proportion. The con- 

 stitution and structure of domesticated animals undoubtedly 

 require that the flesh-forming and heat-generating bodies 

 should be so combined and diluted with neutral ones, that in 

 order to satisfy the appetite and fulfil the designs of nature, 

 they should take in a bulky aliment. Hence the adaptation 

 of grasses and herbs to satisfy the requirements of their sys- 

 tems. The nutritive and heat-generating substances do not 

 differ in kind from those of the seed or even from flesh. One 

 of the questions to be determined then, with respect to grass- 

 es, is the proportions in which these important bodies exist in 

 them. This question is easily settled by an analysis of the 

 plant. The starch, gum, sugar and fat represent the heat- 

 sustaining bodies, the albumen the flesh-forming. A grass 

 will be valuable, all things being equal, in proportion to the 

 latter substance, or any substance which performs a similar 

 office. Grasses which are composed mainly of silica, as the 

 broom-sedge, are never nutritious. Those, however, which 

 are rich in potash and the phosphates of the alkalies, are nu- 

 tritious, and rank high as flesh-forming grasses. As grasses 

 differ among themselves in these particulars, so they differ 

 in their constituents at their different stages of growth. The 

 stem particularly loses its nutritive properties as the seed be- 

 gins to form. At this stage its woody fibre is more dense, it 

 is less palatable, and indeed is passed over entirely by stock, 

 and the softer vegetables consumed in its stead. Hence it is 

 necessary in forming pasturages, to provide a variety of grasses 

 which ripen their seed at different times, and thus furnish a 



