Lesser GHen A Igde 



129 



remarkable diversity of form and of cell grouping among 

 the lesser green algae. 



Botryococcus grows in free floating single or compound 

 clusters of little globose green cells, held together in a 

 scanty gelatinous investment. The clusters are suffi- 

 ciently grape-like to have suggested the scientific name. 

 They, contain, when grown, usually 16 or 32 cells each. 

 They are found in the open waters of bog pools, lakes. 



Fig. 50. Miscellaneous green algas (mostly after West). 



a, Botryococcus; b, Ccelaslrum; c, Dictospharium; d, Kirchnerella; 

 e, Selenastrum; f, Ankistrodesmus falcatus; g, Ophiocytium; h, 

 Tetraspora; i, Crucigenia; j, Scenedesmus;, k, Rhicteriella; 2, ,, 

 Ankistrodesmus settgerus; m, Oocystis. 



and streams, during the warmer part of the season,, 

 being most abundant during the hot days of August. 

 When over-abundant the cells sometimes become filled 

 with a brick-red oil. They occur sparingly in water- 

 bloom. : 

 Dictyosphcerum likewise grows in more or less spheri- 

 cal colonies of globose cells. The cells are connected 

 together by dichotomously branching threads and all 

 are enveloped in a thin spherical mass of mucus. The 

 colonies are free floating and are taken in the plancton of 

 ponds and lakes and often occur in the water-bloom. J 



