22 GRASS LANDS. 



our soil: the meadow poa (p. pratensis), and the 

 rough stalked poa (p. trivialis), when found, are 

 dwarfish ; and having once occasion for a few spe- 

 cimens of the foxtail (alopecurus pratensis) , I found 

 it a scarce and a local plant : but I am convinced, 

 from much observation, that certain species of 

 plants, and grasses in particular, are indigenous to 

 some soils, and that they will vegetate and ulti- 

 mately predominate over others that may be intro- 

 duced. In my own very small practice, a field of 

 exceedingly indifferent herbage was broken up, 

 underwent many ploughings, was exposed to the 

 roastings of successive suns, and alternations of the 

 year under various crops ; amongst others that of 

 potatoes ; the requisite hackings, hoeings, and dig- 

 gings of which alone were sufficient to eradicate 

 any original fibrous, rooted herbage. This field 

 was laid down with clean ray grass (lolium pe- 

 renne), white trefoil, and hop clover, and did toler- 

 ably well for one year : and then the original soft- 

 grass (holcus lanatus) appeared, overpowered the 

 crop, and repossessed the field ; and yet the seed 

 of this holcus could not have lain inert in the soil 

 all this time, as it is a grass that rarely or never 

 perfects its seed, but propagates by its root. The 

 only grass that is purposely sown trefoils are not 

 grasses is, I believe, the ray, or rye, no others 

 being obtainable from the seedsman : this we con- 

 sider 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 



