Bihliogi'aphy. 367 



bility of the laws of nature^ we ought not, perhaps, to be surprised at 

 his discovery of the extraordinary mutation in our northeastern boun- 

 dary, since it was estabUshed by the fathers of our republic. It is 

 quite as likely that landmarks should change their locality, as that ob- 

 jects of natural histoiy should lose the distinctive characters impressed 

 on them by the hand of the Creator." The proportion which grasses 

 bear to other families of plants is next considered ; and we are informed 

 that the grasses of Chester County, native, naturalized, and cultivated, 

 amount to about one hundred species, or one-tenth of the whole number 

 of flowering plants inhabiting the same district ; but, owing to the im- 

 mense number of individuals of many species, their proportion to the 

 actual amount of vegetation is much higher. Their peculiar places of 

 growth, their general distribution throughout the world, and the partic- 

 ular distribution of individuals, the limits and modifications of agricul- 

 ture as produced by climate, or in some degree by national peculiar- 

 ities and customs, are next considered ; and to this follows a brief no- 

 tice of the general properties and uses of this tribe of plants, which, 

 comparatively humble as it is, " probably contributes directly and in- 

 directly, more largely to the sustenance and comfort of the human 

 family, than any, if not all, of the other groups of the vegetable crea- 

 tion." We can cite only a portion of this account. " In an agricul' 

 iural point of view, the superior value of the grasses as materials for 

 pasture and hay, is owing to the large quantity of saccharine matter 

 with which they abound about the time of flowering ; and which is the 

 source of that rich sweet odor observable in well preserved hay. This 

 saccharine matter, which pervades the whole plant before flowering, 

 and is most perfectly elaborated at that epoch, is designed to be ulti- 

 mately concentrated and deposited in the seeds, chiefly in the form of 

 farina ; and hence we find the herbage of comparatively little value 

 after the fruit is fully matured. The skillful agriculturist, therefore, 

 when he wishes to have good hay, cuts his grass at the moment when 

 the nutritious juices are most perfect, and while they are diffused 

 throughout the whole plant. But when his main object is the seed, as 

 in our cultivated grains, he of course postpones his harvest until the 

 career of vegetation is finished. It is needless to enlarge upon the im- 

 portance of the herbage of the grasses, in supplying the food of our 

 domestic animals, and, indirectly, the animal portion of our own food. 

 I will, however, mention those species which are deemed of chief value 

 in our meadows and pastures, — naming them in what I consider the 

 order of their excellence. 1. The meadow, or green grass, erroneously 

 called ' blue grass' in Kentucky, {Poa pratensis, L.) — 2. Timothy, or 

 the ' herd's grass' of the northern states, [Phleum prataise, L.) — 3, 

 Orchard grass, {Dactytis glomerata, L.) — 4. Meadow Fescue, {Fes- 



