86 SMITHSONIAN INSTITUTION 



around like a top. Judging by the puzzled and amused expressions of 

 onlookers, when we embarked within public view, our craft must have 

 been picturesque, to say the least, as it pursued a zig-zag course over 

 the surface of a boggy lake under the erratic control of two-half- 

 dressed limnologists, huddled in the center and leaning over the in- 

 flated pontoon to take water samples in bottles, pulling a little silk net 

 behind, and lifting mud from the lake bottom in a small brass bucket. 



Uncompleted examination of the collections indicates that in gen- 

 eral diatoms flourish much more prolifically in the drainage than in 

 the seepage lakes, in the hard-water than in the soft-water lakes, and 

 in alkaline than in acid waters. The very boggy lakes, high in organic 

 matter and very acid, yielded few diatoms. 



I was so deeply impressed, on a number of occasions, with the strik- 

 ing differences in microscopic life in closely adjacent and apparently 

 similar lakes, which differed only in proportions of dissolved substance 

 by a few parts per million, that I made a point of noting within a 

 period of a few days about August 20 the following lakes, " in bloom " 

 with the corresponding organisms : 



Turtle Lake (Vilas Co. ) Lyngbya, Anabacna 



Fish Trapp Lake (Vilas Co.) Fragilaria crotonensis 



Harvey Lake (Vilas Co.) Fragilaria crotonensis 



Pier Lake ( Oneida Co. ) Fragilaria crotonensis, Asterionclla, 



rotifers 



Grassy Lake (Vilas Co.) Rotifers, Nauplii. (No diatoms.) 



Sweeney Lake (Oneida Co.) Melosira granulata, Stcphanodiscus 



niagarae 



Midge Lake (Vilas Co.) Dinobryon, Ceratium (2 species) 



Scaffold Lake (Vilas Co. ) A very minute blue-green alga species 



Why the differences? That is the problem. It is scarcely conceiv- 

 able, with lakes as old as these and so close to each other, and with 

 diatoms and algae as abundant and easily distributable as they are by 

 birds, water currents, winds, and other agencies, that all the different 

 species would not have had full opportunity for widest distribution 

 in all the lakes. To determine the reasons why some organisms abound 

 to the exclusion of others is a delicate and complex problem. The job 

 of exploring Wisconsin lakes is scarcely more than begun. 



