24 WILD PLANTS. 



others being obtainable from the seedsman : this we 

 consider as perennial ; yet, let us lay down two pieces 

 of land with seeds, from the same sack, the one a low, 

 moist, deep soil, the other a dry upland, and in three 

 or four years we shall find the natural herbage of the 

 country spring up, dispute and acquire in part possession 

 of the soil, in despite of the ray-grass sown : in the 

 deep soil, the predominant crop will probably consist of 

 pose, cockfoot, meadow-fescue, holcus, phleum, foxtail, 

 &c. ; in the dry soil it will be dogstail, quaking grass, 

 agrostis, &c., not one species of which was ever sown 

 by us. It appears that the herbage of our poor thin 

 clay-lands is the natural produce of the soil, for every 

 fixed soil will produce something, and would without 

 care always exclude better herbage. Attention and 

 manures, a kind of armed force, would certainly support 

 other vegetation, alien introductions, for a time, but the 

 profit would not always be adequate. In a piece of 

 land of this nature I have suppressed the natural pro- 

 duce, by altering the soil with draining, sheep-feeding, 

 stocking up, and composting: and scabious, carnation 

 grass, mat grass, and their companions, no longer thrive ; 

 but if I should remit this treatment, they would again 

 predominate, and constitute the crop. 



Most counties seem to have some individual or spe- 

 cies of wild plants predominating in their soil, which 

 may be scarce, or only locally found in another ; this is 

 chiefly manifested in the corn-lands for aquatic or al- 

 pine districts, and some other peculiarities, must form 

 exceptions. This may be in some measure occasioned 

 by treatment or manure, but commonly must be attrib- 

 uted to the chemical composition of the soil, as most 

 plants have organs particularly adapted for imbibing 

 certain substances from the earth, which may be reject- 

 ed or not sought after by the fibrous or penetrating 

 roots of another. Festuca sylvatica abounds in every 

 soil without an apparent predilection for any one : F. 

 uniglumis, only where it can imbibe marine salt: F. 

 pinnata, is found vegetating upon calcareous soils alone, 

 and I have known it appear immediately as the limestone 

 inclined to the surface, as if all other soils were de- 





