in a narrow compass in thick woods and forests l ; and 

 further, that the roots spread much farther on the 

 windward than on the sheltered side of a tree, in order 

 to form a secure hold-fast ; while the branches spread 

 least in the windward side. Advantage is taken of this 

 law by the Dutch gardeners, who rear fruit trees in 

 garden-pots, for the roots being thus kept confined, 

 prevent the branches from spreading. 



In palms and pines, on the contrary, the lofty stems 

 arise from very short roots ; and many slender herbs, 

 such as lucerne and rest harrow, have very long roots. 



The perpendicular extent of roots depends greatly 

 on the looseness or compactness of the soil ; Du Hamel 

 thence found the root of an oak, sown in a rich deep 

 soil, to be four feet in length, while the stem rose only 

 six inches. 



In lichens which encrust rocks, walls, and the bark 

 of trees, I am disposed to consider the whole under 

 surface of the plant as the root, which always clings 

 with more or less firmness to the spot where it grows. 



A root usually consists of several parts, the body, 

 the collar or life-knot, the branches or radicles, when 

 such exist, and the rootlets or small fibres which seem 

 to be indispensable in all roots. 



The body of the root 2 , which is sometimes termed 

 simply the root, varies greatly in form in different spe- 

 cies. It may be vertical 3 , spindle-shaped 4 , conical 5 , 



(1) See ALPHABET OF SCIENTIFIC GARDENING, page 31, &c., 

 where illustrative figures are given. 



(2) In Latin, Caudex. (3) In Latin, Perpendicular is. 

 (4) In Latin, Fusiformis. (5) In Latin, Conica. 



