So ROMANCE OF LOW LIFE AMONGST PLANTS. 



ALG^. 



UNDOUBTEDLY the Alg^ form a very large 

 section of the lower cryptogamia, although at 

 present it is difficult to arrive at any definite census 

 of their number. The exceptions are so few that 

 they may be characterized as truly aquatic, inhabit- 

 ing either fresh water or salt, throughout the world ; 

 but, although often attached by a rooting base, yet 

 destitute of true root, and not obtaining any susten- 

 ance from the object that supports them, but from the 

 medium in which they grow. When it is I'emembered 

 that the Diatomacea^, and the Desmidiaceas are both 

 included in AlgcE, as well as the Confervze of our 

 ditches, and the gigantic sea-weeds which form floating 

 banks in the ocean, it must be admitted that, in size 

 as well as appearance, they present an infinitude of 

 variety. 



If we go back to the estimates of 1847 we shall find 

 that the total of Diatomaceae was then estimated at 

 457 ; of the Confervaceae, which included the Des- 

 midiaceae, at 368 ; the Fucaceas at 452 ; and the 

 Ceramiaceae, almost equal to Floridcae, at 682, with the 

 Characeae at 35 : making in all a total of scarcely 

 two thousand species for the whole world. As afford- 

 ing evidence of the progress made in this department 



