8 
Although the problem of the maintenance and development of 
favorable conditions in this stream is by these facts made somewhat 
special, in many of its general features the Illinois is virtually like 
all other rivers, and a satisfactory program for its investigation 
would be readily adaptable, I believe, to many other streams, and 
applicable in its main features to rivers in general. It is for these 
reasons especially that I have ventured to ask the attention of this 
broadly representative body to my special topic, and to ask your 
criticism of its proposals now, when criticism can be made most 
profitable. 
Versed as you are in the literature and accepted methods of fish- 
culture, I scarcely need remind you that principles of management 
and methods of protection and improvement are not nearly so well 
settled for the fisheries of our natural waters as they are for fish- 
culture in artificial ponds, and that the maintenance and utilization 
of our fisheries has been much less thoroughly studied for rivers, 
either in this country or in the Old World, than it has for lakes. 
This is, no doubt, in part because lake fisheries are, generally speak¬ 
ing, both more important and more readily controllable than river 
fisheries, and partly because the river problem is much the more 
complicated and difficult of the two. The Illinois river has, how¬ 
ever, so many lakes in its bottom-lands, merged with it in times of 
flood, distinguished from it successively with the retreat of the 
overflow, but connected with it and contributing to it at its lowest 
levels, and the river itself has, as a home for fishes, so many of the 
characteristics of a lake, that its problems, although complex and 
difficult, do not compare unfavorably in importance with those of 
any lake in the world of equal area. Its average fall through the 
lower four-fifths of its course is only i% inches per mile, and 
there are stretches of several miles throughout which its fall per 
mile is only about a quarter of an inch. Its current at low water, 
as it swings from side to side of its broad and level flood-plain, is 
as slow, at the dams, as half a mile per hour, and although the mid¬ 
stream flow at high water is of course much stronger, there are 
even then extensive backwater shallows in which a fish could hardly 
tell whether it was swimming upstream or down. 
It is one of the most interesting features of our field of opera¬ 
tion that we are able to bring easily into comparison the system of 
life in this sluggish, lake-like stream with that of the swift Missis¬ 
sippi, into which it flows, or that of the still swifter Missouri, whose 
mouth is only twenty-four miles from its own. Even the Ohio, very 
