TIIALLOrilYTES. 449' 



144. The highest forms of the Algce are the proper Sea- 

 weeds, "some of which have stems of enormous lengths, 

 and fronds that rival in expansion the leaves of the Palm." 

 "Others again are so minute as to be invisible, except in. 

 masses to the naked eye." From those we descend by sua- 

 ecssive gradations to simple or branching cells placed end to-. 

 end, such as the green Confervus of our ponds, and many 

 marine forms, in which the organs of vegetation and fructi- 

 fication become at length perfectly indentical, both reduced' 

 to mere cells, and finally as the lowest term of possible vege- 

 tation we have the plant reduced to a single cell, conaiuing 

 granular matter which gives rise to new ones each of which*. 

 at the destruction of its mother cell becomes an independent 

 minium plant, and repeats in turn the same process." 



145. " The lowest group of the Alga), called Diatomac.e 

 presents peculiarities of the most striking resemblance to 

 those of animals, so that they are claimed at the same time 

 by the Zoologist as well as the Botanist. We see not how 

 fliey are to be seperatcd from the vegetable kingdom, espe- 

 cially if they evolve oxygen gas as they are said to do. Bur, 

 wherever the line be drawn, in reaching the borders of the 

 vegetable kingdom, we make the closest possible approach 

 to- the lowest confines of the animal creation !" 



