20 



PLANT LIFE. 



plants of this sort live almost entirely in water or in wet 

 places, and may be conveniently designated as the filamentous 

 algce. 



25. Spirogyra, etc. Among these none are more beautiful 

 or interesting than the filamentous Conjugatae, represented in 



FIG. 24. 



FIG. 25. 



FIG. 26. 



FIG. 24. A cell from filament of Spirogyra. 



ch, chloroplast (there are three in this cell) ; 



/, pyrenoids ; , nucleus. Magnified 200 



diam. After Strasburger. 

 FIG. 25. A cell from filament of Zygnema^ 



showing two stellate chloroplasts, in each of 



which is a pyrenoid, with the nucleus between 



them. Cytoplasm poorly shown. Magnified 



550 diam. After Sachs. 

 FIG. 26. Two cells from filament of Zygnema, 



showing the gelatinous sheath greatly swollen. 



Magnified 245 diam. After Klebs. 



our waters by the genera, Spirogyra, Zygnema, Mesocarpus, 

 and some others.* They may be readily recognized, during 

 their vegetative period, by their unbranched filaments, bright 



the Conjugate also belong the single- celled desmids already 

 described, 



