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 lime- 

 stone ; 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 na- 

 turally 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 usu- 

 ally, 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 palat- 

 able, particularly to sheep. Where there is a tolerable proportion 

 of argil, we find the cock's-foot (Dactylis glomerata), yellow oat- 

 grass (Avena Jlavescens), crested dog's-tail (Cynosurus cristatus), 

 hard fescue (Festuca duriuscula), smooth-stalked meadow-grass 

 (Poa pratemis), and perennial rye-grass (Lolium 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' Jour- 

 nal for March 3, 1823. 



