ALGiE. 89 



has looked at his specimen carefully, he will pro- 

 bably have observed that different parts of the same 

 specimen were of very different ages ; that though 

 there was no apparent root, yet that toward the 

 centre of the mass a small portion of the stem was 

 of a much darker colour than the rest, and possibly 

 covered by parasitic incrustations, and that all the 

 branches, springing from this central piece, were 

 successively more and more delicate, and of paler 

 colour, and evidently in a young and sprouting state. 

 Such a specimen is clearly in vigorous life, yet it has' 

 no root. But the absence of root is a matter of very 

 trivial moment in a sea-weed ; for we must bear in 

 mind that the roots of Algae are merely holdfasts, 

 intended to keep them from being washed off the 

 rocks on which they grow. And in a plant capable 

 of enduring extensive change of place, like this 

 Sargassnin, the root is the part which may be most 

 readily dispensed with. No doubt the specimen 

 under examination originated in a little branch, 

 accidentally broken from a neighbouring mass, and 

 which, being thus cast adrift, continued to push out 

 new branches and leaves. In this manner, by the 

 continued growth of their broken parts, the floating 

 masses spread over the surface of the sea. In 

 this floating state the species never forms proper 

 fructification. There is therefore no growth from 

 spores. The supply of plants is consequently kept 

 up, and extended, by the constant development of 

 buds, or gejnnice, originating in broken fragments of 

 branches. This process of growth, by breakage, 

 must have gone on for ages, from that early time 



