PHENOMENA OF GROWTH. 51 
would all be cleared up by reference to the well- 
known laws of mechanics or chemistry. But 
the plant is a living being; and that at once 
explains our difficulty, while it leaves us in our 
darkness. 
It must not, however, be supposed that we 
cannot give any account of what takes place: this 
we shall endeavour to give as shortly as possible 
in the clear and concise language of one of our 
most eminent Botanists.* ‘The buds gradually 
unfold, and pump up sap from the stock remain- 
ing in store about them; the place of the sap 
so removed is instantly supplied by that which is 
next it; an impulse is thus given to the fluids 
from the summit to the roots; fresh extension 
and fresh fibrils are given to the roots; new sap 
is absorbed from the earth, and sent upwards 
through the wood of last year, and the phenome- 
non called the flow of the sap is fully completed, 
to continue with greater or less velocity till the 
return of the Winter. 
“The growing point lengthens upwards, form- 
ing leaves and buds in the same way as the parent 
shoot; as horizontal increase of the whole of the 
* Dr. Lindley. Introduction to Botany, 
