434 THE SCIENTIFIC MONTHLY 



A BIOLOGICAL EXAMINATION OF LAKE 

 GEORGE, N. Y. 



By Professor JAMES G. NEEDHAM 



CORNELL UNIVERSITY 



DURING the summer of 1920, the New York State Conservation 

 Commission maintained a field laboratory on Juanita Island in 

 Lake George. The writer was placed in charge. Dr. Chancey Juday 

 of the University of Wisconsin, was at the laboratory in August study- 

 ing temperatures, plankton, and dissolved gases of the lake at different 

 depths. Dr. Emmeline Moore, of the Commission, was detailed to 

 assist in the work of studying the food of fishes and of tracing it back 

 to its sources in the lake vegetation of the shores and of the plankton. 

 State Fish Culturist, Mr. John W. Titcomb, of the Commission, was also 

 present during August studying fishes. Messrs. Charles K. Sibley, of 

 Kingston, N. Y., and William R. Needham, of Ithaca, were regular 

 assistants at the laboratory during the whole of the season. Visiting 

 naturalists who participated to some extent in the work of the labora- 

 tory at times during the summer were Mr. S. C. Bishop, New York 

 State Zoologist, of Albany; Professor C. R. Crosby and Dr. M. D. 

 Leonard, entomologists of Cornell University; Miss Sue J. Reid, secre- 

 tary of the Chicago Nature Study Society, and Miss Jay R. Traver 

 Supervisor of Nature Study at Wilmington, Delaware. The object 

 of this laboratory was to determine conditions in the lake affecting 

 the life of food and game fishes. A report has been made to the 

 commission on fish cultural matters. And at its completion it ha3 

 seemed to the writer that a number of observations made in the course 

 of this work that are of a more general scientific sort might be helpful 

 to other field naturalists and ought to be placed on record: hence, 

 this paper. 



The water of Lake George is "soft"; and the dominant plants and 

 lesser animals are quite different from those of the lakes in Central 

 New York. Doubtless the most abundant plant in the lake — the one 

 that bulks largest — is the stonewort Nitella opaca. It occurs at depths 

 between 18 and 45 feet and covers scores if not hundreds of acres of 

 the lake bed between these depths. It forms great meadow-like beds 

 of erect or recumbent, soft, translucent bright green stems often three 

 or four feet long. These beds (called "grass" by the local fisher- 

 men) furnish shelter and support for a large population of sessile 

 algae; for case-inhabiting insects, such as caddis worms and midge 



