58 THE VEGETABLE WORLD. 
all the future leaves have their development, and it is, in all pro- 
bability, the organ whereby the circulation of the sap is effected 
after the winter’s repose. This growing point has a certain 
analogy with the embryo in the seed, inasmuch as both tend to 
growth and reproduction ; but they differ in this, that the leaf- 
bud needs no fertilisation for its development, and propagates the 
individual as well as the species, while the embryo imperatively * 
needs fertilisation, and continues the species only. 
a ae 
~ 
> 
F 
Dan 
Fig. 72.—Dockweed. 
ens ae 
