10 



Some are so robust, as the Lessonia, &c, as lo be mistaken for 

 wood, when cast in quantities upon ihe shore; so that ships have 

 been laden with them for fuel : others so slemler, as the Conferva, 

 as to comprise a simple filament of single cells. Some are so local 

 in their habits, as to be found only in certain latitudes; others so 

 cosmopolite, as to exlend wherever the ocean flows. Some are con- 

 lined to the close limits of a tide pool ; others, as Sargassum bac~ 

 ciferurn, are wanderers upon the mighty deep, and wilhout a local 

 habitation. But this class of planls, however simple or compound 

 in their structure, are invariably of cellular tissue, and inhabitants of 

 the water. 



In the character of their fructification they are very varied, but 

 differ altogether from every other class in Botany. The three 

 different series, the Olive, Red, and Green, vary so much from 

 each other in this respect, as lo form three natural divisions in 

 Algology. Yet, still the affinity is maintained so as lo bind them 

 together in one class ; but the difference is so great, as not to be 

 admitted within the compass of any order in any of the other series. 



Unimportant as this class in Botany may appear here, in Europe 

 it has not been so consideied, as the laborious woiks of many 

 learned authors can testify. I need only enumerate Dillenius, Hud- 

 son, Stackhouse, Dr. Walker, Dr. Neill, Turner, Dr. Montagne, 

 Milne Edwards, Mr. Ralfs, Sir W. Hooker, Lamaroux, Agardh, J 

 Agardh, Capt. Carmichael, Dr. Greville, Dr. Landsborough, and 

 Dr. Harvey — names of sufficient force to proclaim its importance. 

 Yet, with all the evidences and aiguments these authors have 

 adduced, few things are more common than the question, "Of what 

 use is this study,?" If the replies already written in answer to this 

 inquiry be insufficien!, it appears that noihing can convince such 

 minds. If knowledge for the sake of knowledge itself — if by an 

 augmented knowledge we are exalted above the mere animal — if an 

 •intimacy with the naiural objects by which we are surrounded — if 

 an insight into the living book of God, be of no importance, then, 

 indeed, are arguments vain, anil to such the beauties of God will 

 remain a sealed book, and they may " lay up the talents" which 

 God has vouchsafed them "in a napkin." But there are a few — 

 and that knowledge is refreshing — who delight to search out, and 

 ponder over, and lake pleasure in investigating the infinite harmony 

 and unity of every created thing, and love lo trace such through the 

 affinity and analogy of every object, even the simplest, with the 



