hy Lindlei/s Theory of Horticulture. 463 



by night, are all largely and minutely treated and forcibly 

 illustrated. 



In the last section, of Soils and Manures, the fact that some 

 plants will thrive on very different soils is brought forward; 

 also the little or no difference to be found in the organic state 

 of different species of the same genus, that will not thrive on 

 the same soil ; and consequently the little benefit to be derived, 

 as yet, from the analysis of soils and plants. Generally speak- 

 ing, plants with bushy roots and strong fibres require rich 

 food and plenty of water, as the ash, lilac, privet, balsam, 

 dahlias, celery, leeks, &c. ; and if the soil is light, they will 

 require more manure and water than in clayey soils. Plants 

 that have hard wiry bare roots, as the beech, pines, cistus, 

 larJx, melons, turnips, onions, Stc, require a drier soil, and not 

 so much manure. Plants with very small hairy fibres, as birch, 

 and most of the American shrubs, are fond of a soft adhesive soil, 

 which their roots can penetrate easily, and which will adhere to 

 them ; if leaves are rotted to the consistence of peat, they will grow 

 most luxuriantly among these, either wholly or mixed ; they 

 grow well among peat, but it gets dry and spongy on the surface, 

 and is the better of being mixed with loam and white sandstone 

 pounded ; they will also grow well in soft adhesive loam, espe- 

 cially if mixed with rotted leaves and sand ; a dry stony soil, or a 

 very stiff hard clay, is the worst. But there are many exceptions : 

 the yucca, which is very strong and fibrous in the root, will not 

 thrive well in damp soil; the rose and thorn are both bare- 

 rooted, yet the first can hardly be satisfied with manure, and 

 the last thrives always better in wet than dry seasons ; the roots of 

 oats are, if any thing, smaller than wheat, yet the former thrives 

 better in a wet season than the latter. The genus ^^bies, or 

 spruce, is nearly allied to the Pinus, or fir, and not much apparent 

 difference in the roots ; yet the different species of spruce thrive 

 best in a damp soil, the fir in dry soil. There are constitutional 

 differences in the organisation of the tissue and epidermis of 

 plants, which analysis cannot easily point out ; some plants (and 

 even different parts of the same plant) will secrete poison from 

 the same sap from which others will secrete nutritive food, as 

 some animals will eat with impunity the food which will poison 

 others. Roots will be affected by the warmth and cold of a soil, 

 and the quantity of air which penetrates to them, as well as the 

 state of moisture, and quantity of nutriment. Plants grown on 

 dry loamy soils are more solid in the tissue, hardier, and less 

 liable to be affected with changes, and are best for transplanting. 

 On the section Bottom Heat, we took notice before of the cold- 

 ness and lateness of clayey 'soils, and the warmness, earliness, 

 and rapidly exhausting nature of sandy soils. Much of the bene- 



H H 4 



