THE GREAT GROUPS OF ALG.E 



245 



springs. The filaments are simple, and are not anchored by 

 a special basal cell, as in Ulothrix and Edogoiiium. The 



Ft 1 Sy 77? , 1 C njn„ tc f rm, "^1 \\ n^ on c n j 1 t II ai 1 f rti n of 

 two others. The baml-like chloroplaste extend in a spiral from one end of the 

 cell to the other, in them are imbedded nodule-like bodies i pijrenoids), and near 

 the center of the clO) the nueleiiB is swung by radiating strands of cytoplasm. — 

 Caldwell. 



cells contain remarkable chloroplasts, which are bands pass- 

 ing spirally about within the cell wall. These bands may 



Fig. 213. Spirogyra. showing conjugation ; .4, conjugating tubes approaching each 

 other; B, tubes in contact but end walls not absorbed: C tube complete and con- 

 tents of one cell passing through; D, a completed zygospore.— Caldwell. 



