20 



PLANT LIFE. 



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

 places, and may be conveniently designated as the filamentous 

 algcB. 



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

 or interesting than the filamentous Conjugate, represented in 



\®S 



Fig. 25. 



It 



Fig. 



Fig. 26. 



Fig. 24. — A cell from filament of Sj>irogyr-a. 



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



/, pyrenoids ; k, 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 y 



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 



*To the Conjugate also belong the single-celled desmids already 

 described. 



