58 



and the local and seasonal distribution of each, is a related 

 subject also requiring the resources of an institution, and has 

 consequently been entered upon by us recently. 



Another topic likewise beyond the reach of ordinary agencies 

 is the study of the whole system of the minute plant and animal 

 life of the waters of the state — the so-called plankton, — and in 

 this field extensive researches were made by us during five 

 successive years, from 1894 to 1899, by means of a biological 

 station equipment maintained on the Illinois River at Havana, 

 in which practically continuous work was done throughout the 

 year. This is by far the largest and most elaborate study of 

 the plankton of a river system ever prosecuted, and a part of 

 its results — those pertaining to the plankton of the main stream 

 — have been published by us in two volumes of the Bulletin, 

 containing 890 pages of text and illustrated by fifty-six plates. 

 Although strictly scientific in its aims and methods, this aquatic 

 work lies really at the foundation of intelligent fish-culture, 

 the plankton of our waters being an important element in the 

 food of the young of all fishes, and hence an important part 

 of the natural resources of the state. 



The publications of the survey thus far include eight volumes 

 of bulletins, — the last not yet complete, — containing 4224 pages 

 and 246 plates, and three volumes of final reports — two on the 

 birds and one on the fishes of the state, the latter accompanied 

 by a separate atlas of 102 maps. 



Some of the more important papers of the bulletin series are 

 those on the food of birds, fishes, and insects, already referred 

 to, and descriptive articles on the Hcpaticac of North America 

 and on certain families of fungi ; lists and descriptions of 

 lllintns fishes; several articles on the Crustacea of IllincMs ; 

 studies on the contagious diseases of insects, nijade especially 

 with reference to their economic utilization ; descriptive papers 

 on Illinois reptiles and amphibians; a paper on the animals of 

 the .Mississij)])i boUonis near Ouincy ; many articles on various 

 families of Illinois insects; a study of the entomology of the 

 Illinois River and adjacent waters; numerous studies of the 

 earthworms of the state and their allies; papers on the Proto::oa 



