HORTUS GRAMINEUS WOBURNENSIS. 335 



observations on soils, stated at page 123 et seq. he will find 

 some hints on this important point. 



Mr. Taunton, in his valuable observations on down grasses,* 

 states, that the principal strata which afford downs, are, first, and 

 most extensively, the chalk, including the wolds in Yorkshire ; 

 secondly, in order of succession, the green and brown sand (though 

 these sometimes degenerate into such acerbity, that the heath 

 (Erica vulgaris. Erica tetralix, et Erica cinerea,) is abundant, and 

 they therefore form an exception to the general character of 

 downs, whose produce should principally consist of the natural 

 grasses, and which circumstance distinguishes downs from heaths 

 properly so called); next the oolites or calcareous free-stones, upon 

 which the wolds of Gloucestershire are found ; next the mountain 

 limestone ; and, lastly, certain elevated portions of the killas, or 

 slate. All these downs unite in a few general characteristics. 

 The soil is generally thin, dry, light, and porous : from its eleva- 

 tion it is also usually cold, and backward of growth. In conse- 

 quence of being continually and perfectly ventilated, these pastures 

 are particularly healthy for sheep : by reason of their not being 

 naturally rich, though for the most part easy to work, they are also 

 better adapted for the alternate husbandry, including turnips, than 

 they are for meadow or pasture for heavy beasts : there are, how- 

 ever, some few parts where either a cap of strong soil left on the 

 summits, or a greater depth of alluvial soil washed together into 

 hollows, throws out a pasturage so strong that a cow can obtain a 

 tolerable bite, and such parts obtain the honourable pre-eminence 

 of being called cow-leazes. The upper soil of these tracts is 

 usually, in a principal degree, calcareous, with a greater or less 

 mixture of siliceous sand, and some portion of argillaceous matter. 

 In some spots the. argil, in some the silex, in some the calcareous 

 matter predominates. The natural grasses which generally abound 

 in these downs are of small bulk, but they are wholesome and pa- 

 latable, particularly to sheep. Where there is a tolerable propor- 

 tion of argil, we find the cock's-foot {Dactylis glomerata), yellow 

 oat-grass {Avenajiavesceris), crested dog's-tail {Cynosurus cristatus), 

 hard fescue (Fesfuca durinsciila), smooth-stalked meadow-grass 

 {Poa pratensis), and perennial rye-grass (Lo/iiim perenne), most 

 prevalent, but not to the exclusion of others. Where the siliceous 



* See a letter under the signature of " A Surrey Farmer," in the Farmers' 

 Journal for March 3, 1823. 



