CHAPTER XX. 



FRESHWATER WEEDS. 



" And there, to charm the curious * 

 A host of hidden treasures lie, 

 A microscopic world that tells 

 That not alone in trees and flowers 

 The spirit bright of Beauty dwells, 

 That not alone in lofty bowers 

 The mystic hand of God is seen, 

 But more triumphant still in things men count as mean." 



Gardener. 



^^^f HE green Algae seem a much smaller group than 

 the red and the olive, but this is not really the 

 case. A large proportion of them inhabit 



freshwater and damp ground, and are therefore separated 

 from the sea-weeds, though nearly allied to them in 

 nature ; and a vast number again belong to the entirely 

 microscopic orders, Desmidiaceae and Diatomacese. 



In the same group with our marine friends, Codium 

 and Bryopsis, we find the extensive family of the Yau- 

 cherias, so called from their historian Yaucher. The 

 three salt-water species are very inconspicuous. The 

 Forked Vaucheria (Y. dichotoma) is a much larger 



