Maech 9, 1900.] 



SCIENCE. 



377 



Crustacea may be said to date back only 

 half a century to the writings of Fischer 

 and Claus, although some papers upon this 

 subject had been published previously. 



In 1817 Say published a somewhat ex- 

 tended article on the Crustacea of the 

 United States, in which he speaks of one 

 Ostracod, two Daphnias and one Cyclops, as in- 

 habiting the waters of the southern states. 

 In 1843, in the ' Natural History of New 

 York, ' was published an article by DeKay on 

 the Crustacea, which was beautifully illus- 

 trated, but added little to our knowledge of 

 the fresh water Crustacea. In fact, though 

 Cyclops and Daphnia are mentioned, they are 

 spoken of as ' extra-limital,' in spite of the 

 fact that not a lake in New York would 

 have failed to furnisb him countless num- 

 bers of these genera, had he looked for 

 them. To Professor Forbes, of the Uni- 

 versity of Illinois, is due the credit of mak- 

 ing the first extensive collections of these 

 animals in this country, and publishing 

 accurate descriptions of them. His first 

 paper was published in 1876, and was fol- 

 lowed by a series of very valuable investi- 

 gations, culminating within the last few 

 years in the establishment of a floating 

 laboratory on the Illinois River for the 

 continued study of the fauna and flora of 

 that river and the shallow lakes adjoining. 



In Europe large numbers of investiga- 

 tors within the last few years have devoted 

 themselves to the study of fresh water 

 animals and plants. Preeminent among 

 them have been Forel and his co-laborers 

 on Lake Leman, and Zacharias and his fel- 

 low-workers in the station at Lake Plon in 

 Holstein. This station at Plon was, I be- 

 lieve, the first permanent fresh water sta- 

 tion in the world. Since its establishment 

 in 1891, a considerable number of perma- 

 nent stations have been established in 

 various parts of the world. It is not my 

 purpose here to give a history of these 

 establishments, for that has already been 



exceedingly well done by Professor Ward. 

 I may call attention in passing, however, to 

 the fact that the work in this country has 

 been done almost exclusively in our imme- 

 diate vicinity, Illinois, Wisconsin and 

 Michigan having published by far the most 

 material on this subject. Similar work has 

 been prosecuted in Minnesota, Ohio and In- 

 diana, but very little has been done in the 

 other states, if we except the exceedingly 

 valuable work of Whipple. 



In Wisconsin, work has been prosecuted 

 on the Madison lakes and Green Lake for 

 many years, and now, under the auspices 

 of the Natural History Survey, a more ex- 

 tensive and systematic biological survey of 

 the lakes is being made, probably a more 

 extensive comparative study than has been 

 attempted elsewhere. While this study is 

 of especial scientific interest, as has been 

 intimated before, it is of great practical in- 

 terest in connection with the problems of 

 fish culture. It may not be likely that, as 

 suggested by a recent writer in Forest and 

 Stream, the future angler will carry with 

 him a thermometer and chart with a state- 

 ment of the laws of vertical and horizontal 

 distribution, but such study does give a 

 fundamental knowledge which is of vast 

 importance to the angler as well as to the 

 fish culturist. 



The terminology used in the study of the 

 fauna and fiora of fresh-water lakes, as in 

 the sea, was formulated by Hackel. Under 

 the term ' plankton ' is included all living 

 things, animal or vegetable, found in the 

 water which do not move from place to place 

 by their own volition. Fishes are not con- 

 sidered a part of the plankton. The life of 

 the sea may be considered as ' littoral,' ' pe- 

 lagic ' and ' abyssal. ' To these terms Hackel 

 adds ' zonary,' to include those animals 

 which are supposed to occur at zones of dif- 

 ferent depths in the open ocean. In the lit- 

 toral and pelagic planktons we may have 

 both animals and plants, but in the abyssal 



