60 THE LIFE OF DEA^LR LAKE 



questionably influenced the numbers of bacteria in Minnewaukan 

 Bay and possibly to some extent in the main lake at this time. 



None of the bacteria in Devils Lake occur uniformly in all of 

 the eollectious, altho most of them occur frequently. In most cases 

 their presence is apparently accidental and not characteristic. 



The list of species identified is probably incomplete ; which, 

 coupled with the irregularity in their occurrence and the lack of 

 adequate data regarding- each, prevents a detailed discussion of them 

 here. 



Bacillus subtilis appears to be the commonest bacterium in the 

 lake, but it is difficult to make any selection among the others. 



The list follows: 



Micrococcus candicans, citreus, descidena. orbicularis, plumosus. 

 radiatus, rosettaceus, simplex. Streptococcus albus, vermiformis. 

 Sarcina alba, lutea, subflava. Bacillus aerogenes, albus, aquatilis, 

 coli communis, convolutum, fluorescens, formosus, proteus vulgaris, 

 reticularis, subtilis, vermiculosura, Bacterium aerogenes, desidiosum, 

 flexuosum, nubilum, tiogense. 



ALGAE 



Of the algae the blue-greens and diatoms furnish by far the 

 greatest number of species, the three most characteristic genera 

 being Nodularia, Coelosphaerium and Chaetoceros. Many of the 

 species described do not occur, or cannot be recognized, in the 

 planeton samples, due in part to their rarity, in part possibly to 

 poor preservation, in part to the difficulty of recognition under the 

 low magnifications used in counting and in part to their presence 

 chiefly among attached algae, where the samples were not taken. 



Dr. George T. Moore who has made a preliminary report on 

 the Myxophyceae and Chlorophyceae of Devils Lake (1917) says: 

 "The algal flora of Devils Lake can hardly be regarded as a 

 rich one. The Myxophyceae are, it is true, fairly well represented, 

 and the fact that they constitute practically 50 per cent of the 

 genera and species present* may be regarded as one of the effects 

 of the increasing salinity of the water. The almost entire elimina- 

 tion of the Conjugales, which so frequently constitute the greatest 

 number of species in fre.sh-water lakes, is likewise to be attributed 

 to the high content of salts, and perhaps the absence of this order 

 is sufficient alone to account for the small total number of species. 

 With the exception of Spirulina nordstedtii,* all the species listed 

 are frequently, if not invariably, found in fresh water, so that the 

 algal flora of the lake is to be regarded as typically a fresh-water 

 one, showing no effect of the gradual concentration of the water. 



♦Not inrludlng thp diatoms. 



•Subtllissima is also present. Moore describes it as "a salt water and sulphur 

 spring form." 



