220 HORTUS GRAMINEUS WOBURNENSIS. 



the operation will be performed in the dark, and conse- 

 quently with less certain success. If the reader will look 

 back to the observations on soils, 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 York- 

 shire ; secondly, in order of succession, the green and brown 

 sand ; though these sometimes degenerate into such acerbity, 

 that the heath (erica vulgaris, erica teiraiix, et erica cinerea) 

 is abundant, and they therefore form an exception to the 

 general character of downs, whose produce should princi- 

 pally consist of the natural grasses, and which circum- 

 stance 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 cha- 

 racteristics. The soil is generally thin, dry, light, and 

 porous : from its elevation it is also usually cold, and back- 

 ward of growth. Tn consequence 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 pie-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, pre- 

 dominates. The natural grasses which generally abound 

 in these downs are of small bulk, but they are wholesome 

 and palatable, particularly to sheep. Where there is a 

 tolerable portion of argil, we find the cock's-foot (dactylis 



