504 



SCIENCE. 



[N. S. Vol. IX. No. 223. 



ton is the first general statement of the 

 problems and of the methods used by Hen- 

 sen in the investigation of the marine life 

 with such success, and by Apstein first ap- 

 plied to lacustrine investigation. Prob- 

 ably the best known fresh- water station in 

 the world is that on Lake Ploen also in 

 Holstein. This was the first permanent 

 general fresh- water station to be established 

 in the world. It owes its inception to the 

 energy of its present director, Dr. Zacharias, 

 whose plan was to establish for fresh water 

 an institution similar to the ISTaples marine 

 biological station. The station opened in 

 1891, and since that time it has been in 

 continuous operation, and has afforded 

 opportunities for investigation to a large 

 number of scientific workers both German 

 and foreign. It is the most pretentious of 

 all fresh-water stations, having a building 

 two stories in height, with numerous labo- 

 ratory rooms and equipped with abundant 

 apparatus for collecting and investigating. 

 From it has been published yearly, since 

 1893, a volume of studies, and the director 

 has also contributed largely to other jour- 

 nals on these problems. Two other stations 

 in Germany owe their inception to the 

 fishery problem, and have for their purpose 

 more particulai'ly the investigation ofthose 

 limnologic questions which deal particularly 

 with the life of the fishes. One of these is 

 located at Miiggelsee, near Berlin, and is 

 conducted under the auspices of the Ger- 

 man Fishery Association. The other, at 

 Trachenberg, is under the auspices of the 

 Silesian Fisheries' Association. Both have 

 made important contributions to the bio- 

 logical questions concerned in fish culture. 

 All the North American stations which are 

 known to me lie within the limits of the 

 United States, and they represent all the 

 various types of such institutions. A con- 

 siderable number of workers have reported 

 isolated investigations of lakes in all parts 

 of the country from Maine to California. 



Among the most important of these occa- 

 sional observations are those made by 

 Forbes on the fauna of elevated lakes in the 

 Eocky Mountains. The observations which 

 he has recorded were made in the course of 

 a preliminary investigation of these lakes 

 by the United States Fish Commission, and 

 constitute the only information on record 

 with reference to the lakes of the country 

 west of the Missouri river. There are but 

 two localities which may be listed, however, 

 as individual resorts sufficiently I'egularly 

 visited to entitle them to more particular 

 mention in this place. Green Lake, in 

 Wisconsin, has been carefully studied hy 

 Professor Marsh, of Ripon College, and his 

 work has yielded valuable information with 

 reference to the vertical distribution of the 

 Crustacea and with regard to the deep water 

 fauna of the lake. Here he was able to 

 confirm the observation of Stimpson, on 

 Lake Michigan, that there are found in the 

 deep waters of our large lakes Crustacea of 

 a purelj^ marine type. At Lake Mendota, 

 in AVisconsin, on the shores of which is lo- 

 cated the State University, a careful inves- 

 tigation, extending over a verj^ considerable 

 number of years, has been carried on by 

 Professor Birge of the University. The i-e- 

 sults which he has obtained with reference 

 to the distribution, both vertical and sea- 

 sonal, have been published by the "Wiscon- 

 sin Academy and are not only the most 

 extensive, but beyond all comparison the 

 most precise investigation which has been 

 made on this problem. 



Of course, in one sense, this station has 

 no building, but the scientific laboi-atory of 

 the University, standing within a stone's 

 throw of the shore of the lake, affords op- 

 portunities which are not surpassed at any 

 fresh-water station in the world. 



Quite a number of periodic resorts of the 

 type of summer laboratories are to be found 

 in various parts of the country. Some of 

 these are merely summer schools, such as 



