REPORT OF COMMISSIONER OF FISH AND FISHERIES. 19 



was made of the fauna, and the conclusion was reached that the 

 abundance of predaceous fishes and the restricted spawning-grounds 

 were responsible for the failure of the salmon to maintain itself. 



The biological survey of Lake Erie was continued during July and 

 August under the direction of Prof. Jacob Reighard. The hatchery 

 at Put-in Bay was used as laboratory and headquarters, but various 

 other parts of the lake were visited by members of the party. An 

 account of the work is elsewhere given in the report.* 



A comprehensive study of the waters of the hydrographic basin of 

 the Wabash River, Indiana, was undertaken by the Commission dur- 

 ing the summer of 1899. A number of the lakes and rivers were 

 studied with some care, but principal attention was paid to Lake Max- 

 inkuckee, in Marshall County. Maxinkuckee is typical of the small 

 glacial lakes of the L^pper Mississippi Yallej^ and it was considered 

 that a thorough investigation of the biological and phj^sical features of 

 its waters would develop facts common to all of the lakes of its class. 

 The work began July 1 and was continued until the latter part of 

 October by a party under the direction of Prof. B. W. Evermann. A 

 topographic and hydrographic survey was begun, meteorological 

 observations were carried on, collections were made illustrative of the 

 flora and fauna of the lake and its immediate environment, and data 

 .were obtained concerning the habits and distribution of the various 

 animals, especially the fishes. 



Seneca Lake, in New York, and Lake Mattamuskeet, in North Caro- 

 lina, have been visited and collections of their fishes have been made 

 or arranged for. 



Investigations upon the fishes of the principal river basins in West 

 Virginia, begun in 1899, were conducted by a party under Mr. W. P. 

 Hay, The Potomac, Greenbrier, Elk, and especially the Monongahela 

 river systems were well examined. Until recent years these rivers 

 were productive of fine food-fishes, but of late they have become sadly 

 depleted, principally through the denudation of the forest lands, the 

 pollution of the waters, dynamiting, damming of streams, and other 

 changes in the conditions, principally due to industrial operations. 



On the Pacific coast the studies of the salmon and other fishes have 

 been continued in the eastern tributaries of the Sacramento. The 

 explorations of the coastal streams begun in previous years have been 

 extended between the northern boundarj^ of California and the 

 Columbia River, and a study of the fishes of the San Pedro River has 

 almost been completed. 



Considerable progress upon the study of the collections made by 

 the Fish Haivh in Porto Rico during the winter of 1898-99 is reported. 

 The specimens were distributed among a number of specialists, and 

 many of the reports have been received and several are now in prog- 

 ress. These papers will make an important and attractive publication, 

 which it is hoped to issue during the ensuing year. 



