flora. The decidedly larger number of algal species in the highly 

 basic lakes is related to the richness of the phytoplankton in such 

 habitats. It is in lakes with pH readings such as tliese that blue-green 

 species often produce water blooms. 



As was mentioned previously in another connection, hard water 

 seepage lakes are rather rare. This is seen in Figure 6, which shows 

 a few lakes having a pH between 7.2 and 7.7. In at least one of these 

 lakes the bound carbon dioxide was as high as 14 ppm. In such lakes 

 the green algal species are sometimes three times as numerous as the 

 blue-green. 



A considerable number of soft water seepage lakes were found 

 among those used in this analysis; most of these had a pH between 

 6.0 and 6.8. As with the soft water drainage lakes, the seepage lakes 

 have floras predominantly of the green algal type. It should be men- 

 tioned, however, that some of the soft water seepage lakes have a 

 great bulk of certain blue-green algae, but the number of species is 

 very small. 



[33] 



