90 



PEACTICAL BOTANY. 



Other plants are heterogamous, i.e., the sexual repro- 

 duction is by the union of cells distinctly different from 

 each other. Important orders are the Sphceroplece, (Edo- 

 goniece, and Coleochcetece. 



The (Edogonieae are to be looked for in stagnant and 

 flowing water, either in masses by themselves, or in asso- 



48 49 



FIG. 48. CEdogonium, showing splitting of cells and escape of the ciliated 



zoospores. 

 FIG. 49. CEdogonium. a, zoospore; b-e, young plants. Magnified. 



ciation with other plants. They do not usually grow 

 independently, but are supported by other plants, or are 

 attached to stones and the debris that accumulates in still 

 water. The color is green, or brownish-green. The en- 

 larged cells that they bear at intervals distinguish them 

 from other Green Algse. 



The asexual reproduction of GEdogonium presents some 

 points of interest. Large oval zoospores are formed in 



