88 OF THE ROOT, 



been taken for the true A. bulbosus, t. 1249, which 

 has always bulbs, even in its native marshes. We see 

 the wisdom of this provision of Nature in the grasses 

 above mentioned, nor may the cause be totally inex- 

 plicable. When a tree happens to grow from seed on 

 a wall, it has been observed, on arriving at a certain 

 ,-size, to stop for a while, arid send down a root to the 

 ground. As soon as this root was established in the 

 soil, the tree continued increasing to a large magni- 

 tude*. Here the vital powers of the tree not being 

 adequate, from scanty nourishment, to the usual annual 

 degree of increase in the branches, were accumulated 

 in the root, which therefore was excited to an extraor- 

 dinary exertion, in its own natural direction, down- 

 ward. There is no occasion then to suppose, as some 

 have done, that the tree had any information of the 

 store of food at the foundation of the wall, and volun- 

 tarily sent down its root to obtain it ; nor is it wonder- 

 ful that the Author of life should provide for it as 

 effectually as it eould for itself, had it really been a 

 reflecting being. So in the case of the grasses in 

 question, I presume the herb being in the first instance 

 starved, by a failure of the nutrimental fluids hitherto 

 conveyed by the water of the soil, its growth would be 

 checked, and when checked, the same growth could 

 not, as we know by observation on vegetation in ge- 



* A particular fact of this kind concerning an ash was communi- 

 cated to me by the l-ite Ilev. Dr. Walker of Edinburgh. See also 

 Trans, of Linn. Sjc. r. 2. 268. 



