124 



Aquatic Organisms 



meshed species the inner cells can be seen to meet by 

 threes about the openings, quite as in the water net; 

 but the cells are less elongate and the openings smaller. 

 Five of the seven specimens shown in the figure lack 

 these openings altogether. 



New colonies are formed within single cells, as in 

 Hydrodictyon. In our figure certain specimens show 

 marginal cells containing developing colonies. One 

 shows an empty cell wall from whence a new colony has 

 escaped. 



Other green algce — 



We have now men- 

 tioned a few of the 

 more strongly 

 marked groups of the 

 green algae. There 

 are other forms, so 

 numerous we may 

 not even name them 

 here, many of which 

 are common and 

 widely dispersed. 

 We shall have space 

 to mention only a 

 few of the more im- 

 portant among them, 

 and we trust that 



the accompanying figures will aid in their recognition. 

 Numerous and varied as they are, we will dismiss them 

 from further consideration under a few arbitrary form 

 types. 



I. Simple filamentous forms. Of such sort are 

 Ulothrix, CEdogonium, Conferva, etc., (fig. 45). Ulo- 

 thrix is common in sunny rivulets and pools, especially 

 in early spring, where its slender filaments form masses 



Fig. 45. Filamentous Green Algae. 



a, Ulothrix; b, CEdogonium, showing characteristic 

 annulate appearance at upper end of cell; c. 

 Conferva {Tribonema); d, Draparnaldia, (After 

 West). 



