502 FRESH-WATER BIOLOGICAL STATIONS OF THE WORLD. 



restore their numbers, and it was felt that something must be done by 

 governmental agency to replenish the depleted waters. The first 

 expedient of collecting and keeping under satisfactory conditions large 

 numbers of fish eggs until they should be hatched and the young fry 

 distributed through the waters was not so successful as had been hoped. 

 The x)roblem was too large to be attacked in such a superficial manner, 

 and the further knowledge, which it became clear was absolutely neces- 

 sary for proper handling of the question, must needs be sought through 

 some means for the investigation of the conditions and determination 

 of the steps necessary for the solution of the problem, and for carrying 

 into effect the measures which might afford the desired relief. This 

 led first in Europe, to be sure, in connection with private enterprises 

 for fish culture, to the establishment of biological experiment stations 

 with the fish hatcheries, very much as chemical laboratories are now 

 necessary adjuncts of various manufacturing interests, or agricultural 

 experiment stations are connected with the higher development of agri- 

 cultural possibilities. There is, however, a still further demand which 

 has led to the formation of institutions of the general type which we 

 are considering. The water supply of our cities has always been a 

 serious problem and one of increasing interest in connection with 

 crowded conditions in the more thickly settled countries of the world, 

 and the biological examination of the water, undertaken of necessity, 

 has led to the organization of biological laboratories connected with 

 the water systems of great cities, both on the Continent and in our own 

 country. 



Having thus discussed the causes which have led to the establish- 

 ment of limnobiological stations, we may now consider, briefly, the types 

 which they present, and the particular results which may be expected 

 from a giveu sort. Of course all probable variations may be found, and 

 it is difficult to make any classification which is complete or even just, 

 and yet for convenience we may divide these enterprises into a few 

 great groups, recognizing the fact that certain of them do not belong 

 singly to any one class, but combine features of different types. But 

 before outlining this classification, let me say that I do not regard the 

 existence or nonexistence of a building or structure devoted to the 

 purpose of investigation as a necessary mark of a biological station. 

 Some of the most valuable contributions to general and special ques- 

 tions in this field have come from investigators or groups of investi- 

 gators who have had no abiding place, while, on the other hand, stations 

 well equipped with buildings and apparatus have in some instances, so 

 far as can be ascertained, contributed nothing eveu after several years' 

 existence, to the progress of scientific knowledge. Material equipment 

 is valuable, and in general, conduces to better results, and yet it is the 

 results themselves which finally determine the character of any enter- 

 prise and the position which it should hold it the esteem of the world. 



For the purposes of this discussion I propose dividing biological sta- 



