4 BRITISH SEA-WEEDS. 



answering to the wood, bark, veins, etc., of the stems 

 and leaves of trees and plants. " Passing from such," 

 writes Dr. Harvey, " we meet with others gradually less 

 and less perfect, until the whole vegetable is reduced 

 either to a root-like body, or a branching, naked stem, 

 or an expanded leaf; as if Nature had first formed the 

 types of the compound vegetable organs so named, and 

 exhibited them as separate vegetables ; and then, by 

 combining them in a single framework, had built up 

 her perfect idea of a fully-organized plant. But among 

 Algse we may go still lower in vegetable organization, 

 and arrive at plants where the whole body is composed 

 of a few cells strung together, and finally at others — 

 the simplest of known vegetables — whose whole frame- 

 work is a single cell" 



The root of a Sea- weed is either in the form of a disc, 

 or, more rarely, fibrous. It is small in proportion to 

 the size of the plant, and in some species is quite ob- 

 scure, or altogether absent. 



It does not absorb and transmit nourishment, like the 

 root of a more highly-organized plant, and indeed its 

 sole function is to serve as a means of attachment. It 

 does not penetrate the rock or other substance to which 

 it may be affixed, but simply clings to the surface. This 

 it does more or less firmly in proportion to the resist- 

 ance that it has to offer to the action of the ever-moving: 

 sea, and great indeed must be the power which the roots 

 of the larger Fuci have to exert in order to maintain 

 their position on rocks exposed to the full sweep of the 

 ocean waves in all their vicissitudes of mood, from calm 

 to raging storm. 



The term frond, strictly speaking, includes all the parts 

 of a Sea- weed, except the root and the fructification. 



