may be here mentioned, although it grew out of our aquatic work outside the Illinois basin. One large section of the State of Illinois, comprising about a fifth of its area, is peculiar in the absence, or at least in the unusual rarity there, of a considerable group of fishes which are abundant elsewhere in the state and elsewhere in the surrounding territory. Now this section, the conditions of which these fishes evidently do not tolerate, is distinguished from the remainder of the state by its geological history, and, as a consequence, by the different character of its soil and of its streams. The soil is so finely divided that its particles cannot be wholly separated from the water, even by repeated filtering with the finest filter papers, and it thus remains persistently and perpetually turbid. The fishes which seem to avoid this situation are, on the whole, those which we find in other parts of the state to be relatively infrequent in very muddy water. The inference is plain that it is the permanently muddy character of these southern Illinois streams, itself due to the geological history of the district, which renders them unfit for these more sensitive fishes. Any attempt, consequently, to increase the number of such fishes there would be foredoomed to failure. Doubtless there are many other instances of the same sort to be found in other parts of the country, and it seems possible that various mysterious failures of attempts made to introduce new fishes are attributable to some such cause, not taken into account because unknown. We have now a long waiting list of special practical inquiries which seem clamoring to be made. We need, for example, to observe most carefully the European carp, now undergoing enormous multiplication in our interior waters; to learn the details and the variations of its food and its habit under different conditions; to study the bearings and consequences of its spread and increase on the welfare of our native fishes, and on the whole system of fresh-water life; to watch for evidences of local overpopulation by it, to be suspected when the carp or its competing species fall below the average in size and plumpness, or when epidemic diseases appear among them; to follow the course of events in its principal spawning grounds, where our own observations show that tremendous losses, amounting to a local extermination of the young, may occur under usual conditions; and to determine, by the use of numbered tags, the range of the wanderings of this and other fishes, and especially to learn how far the various species usually go from the places where they were hatched. We have a rare and remarkable opportunity in Illinois to watch the progress of a biological revolution as important to the life of our waters as was the Norman invasion to the life and history of England. Fortunately, we have for comparison with present and future conditions, the materials and records of several years' systematic and connected work done on the Illinois River before the opening of the drainage canal into Lake Michigan, and when the carp was but just beginning to make its presence felt as a disturber of the then existing order. I cannot, within the time limits of your program, go further with the development of this subject, and I must content myself with these sample fragments of its discussion. When the results of our river work began to appear several years ago, a leading American zoologist wrote me that the Illinois promised to become very soon the best known-because the best studied-of any river in the world, and we have been at work a good deal of the time since in an effort to increase still further our knowledge of that stream and the public appreciation of its value. In the face of the gigantic interests—agricultural, industrial, commercial, and political—which are now mustering along its course, with huge schemes in hand for revolutionary operations upon its channel, its banks, and its backwaters, we feel that we need all the backing and assistance we can secure from those concerned in the preservation and development of our native fisheries; and no agency, I am sure, is in a position to give us more effective aid than this old and influential American Fisheries Society. Especially we shall value your suggestions both as to subjects deserving early investigation, and as to practical measures possible and desirable on the basis of such knowledge as we now have or may presently acquire. DISCUSSION PROFESSOR FORBES (before reading his paper): I think myself fortunate this morning in the fact that the opening address of yesterday forenoon and the very animated and earnest discussion which followed upon that address yesterday afternoon, were in a great measure an opening up of the subject of which my paper will be a special illustration and a concrete instance. I am to deal with a specific problem in the general field of the conservation and improvement of our national aquatic resources; and the very able and comprehensive way in which this subject was handled by Dr. Townsend and the interesting and effective manner in which the discussion was taken up by Mr. Clark, Mr. Meehan and others yesterday seemed to me a happy preparation for the task which I have undertaken. PRESIDENT: I do not know how the rest of the members of this Society feel in regard to that paper, but I call it a classic, and it almost seems like desecration to attempt to add to or take from it. DR. C. H. TOWNSEND, New York: I do not know when I have listened to a more admirable paper at the meetings of this Society. We have long been familiar with the very remarkable fish catch of the Illinois River. There is nothing like it in the country. I am sure we are all very much indebted to Professor Forbes for setting forth the method of his admirable work and the work of his assistants in studying the biology of this river. PRESIDENT: Are there any further remarks in connection with this very able paper? MR. JOHN W. TITCOMB, Lyndonville, Vt.: I cannot help expressing my enthusiasm at this paper. I enjoyed it very much. I wish we could have more like it from other states. It was a very thorough paper indeed. DR. R. C. OSBURN, New York: Would Professor Forbes kindly tell us whether in his opinion sewage will not prove deleterious to other varieties of fish life in Illinois? PROFESSOR FORBES: I suppose different fish populations would be affected differently by additions of still more dirt or filth from the contents of the river; but the fishes of the Illinois River are pretty well hardened to conditions which fish of clear lakes and streams would find intolerable. It may be that in course of time we shall find deposits on the bottom which undergo decomposition which will make them injurious; but up to the present time we have not been able to see any injurious effects at all upon the fisheries of the river or its waters as a consequence of contributions of Chicago sewage, which, however, under |