CONFERVOIDE.E ISOGAM.-E 



275 



spores put out an organ of attachment even before they germinate. In 

 Chaetophora and otlier genera which make up the Chaetophoracese of 

 Hassall, the terminal cell of the main axis or of its branches is prolon^^ed 

 into a colourless hyaline bristle. These are especially well developed 

 in Draparnaldia, an exceedingly beautiful organism not uncommon in 



Fig. -zjf^.- Draparnaldia gloiiierata Ag. (^x. 100). (From nature.) 



freshwater, which exhibits a somewhat higher type of development than the 

 other genera, being differentiated into an axis or central tube, and smaller 

 secondar)^ branches arranged in regular whorls ; the zoospores being 

 produced in the latter only. Maupas states (Compt. Rend., Ixxxix., 1879, 

 p. 250) that the cells of Cladophora contain a large number of nuclei ; 

 and Schmitz (Sitzber. Xiederrhein. Gesell., 1879) finds four nuclei in a 



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