5. Statistics of the run of salmon.-During the years that the studies outlined above are being made on the streams, statistics of the run of salmon of each stream should be made. The primary object of these studies would be to determine the total number of fish of each particular stream for each of a series of years. If the investigation is properly made, the total run of each stream would be the number of fish headed for that stream taken by the fishermen, plus the escapement as determined by the census at the rack, plus a negligible few that escaped observation. These data, for a series of years would, it is believed, supply a ratio between the number of fish in the escape and the total run which will show the number of fish that must be permitted to escape to the spawning beds to maintain the fishery at a maximum annual pack. SUMMARY The essential features of the plan here proposed for the rehabilitation and conservation of the Alaska salmon fisheries may then be summarized as follows: 1. Rack every stream that can be racked and make an accurate count of the salmon ascending it. The census or count must be made often enough to cover at least two returns of each annual run of the first two or three years. 2. In each of the years in which a census of the spawning fish is made, secure statistics showing the number of fish taken by the fisheries from the run of that river. This number plus the escape let through the rack will be the total run of that year. From these data the proper ratio of escape to catch can be determined. 3. Study each spawning bed and determine its maximum capacity, giving attention at the same time to the possibility of increasing its area and improving the physical and biological conditions thereon. 4. When all has been done in these respects that can be done or need be done, the capacity of the stream and the maximum catch and escape determined then rack the stream, let through the rack the number of fish which have been found to be necessary to keep up the catch from year to year at the maximum capacity of that stream, close the rack, and then let the commercial fishermen catch in the easiest way they can all the fish that are left.1 This will probably be by means of haul seines which would most likely be operated immediately below the rack where the fish Whether all the spawning reserve be passed through the gates before any fishing is permitted, or whether the gates be closed at intervals and "escape" and "catch" alternate through the season, is a matter of detail which, with many others, may properly be left for experimental determination. would be bunched. All other kinds of gear can then be abandoned-gillnets (fixed and floating), purse-seines, and expensive traps and pounds-all these can be discontinued except in exceptional places. This would mean a very decided change in the methods of the fisheries and an enormous reduction in the cost. A licensing system similar to that employed in the oyster fisheries of the Atlantic and Gulf coasts, or that of the Federal Government regulating timber-cutting or grazing in national parks and reservations, can be devised and put in operation, satisfactory to the fishery interests. During the progress of these investigations fishing off the mouths of a good many of the streams will have to be limited; the run in some streams has already been so seriously depleted that it may be wise to prohibit for a number of years all fishing that draws from their run. The plan here proposed will doubtless meet with strong opposition from the actual fishermen; they will, of course, object to any system which will result in a reduction of the number of fishermen needed to catch the fish. This need not disturb us; the object in view is to maintain the salmon industry as a going concern, not the employment of the greatest possible number of fishermen. It will also be urged that the investigations required to give us the body of facts essential to the development and application of the method here outlined must necessarily extend through a long series of years and are bound to cost enormously. This is perfectly true. It will require several years to determine the details of the methods in accordance with which this great fishery must be conducted if it is to live. The cost will be great indeed; perhaps a million dollars, may be more; but what is that in comparison with the untold billions that will in the years to come be the return from the great fishery which the expenditure of a million dollars during the next decade will insure for all time, but which, unless this or something like it is done and done soon, will very soon cease to exist? THE CHICAGO THE THE PROGRESS OF SCIENCE MEETING OF AMERICAN ASSOCIA-. TION FOR THE ADVANCE MENT OF SCIENCE The seventy-third meeting of the American Association for the Advancement of Science was held in Chicago, from December 27 to January 1. From the account of the meeting printed in Science, the official organ of the association, some data of general scientific interest may be quoted. It was the second of the greater convocation week meetings of the association and of the national scientific societies associated with it, convened once in four years successively in New York, Chicago and Washington. The remarkable scientific activity of the central west and of the reconstruction period following the war were adequately reflected by the attendance and programs at Chicago, which have probably not been surpassed by any previous gathering of scientific men in this or any other country. In addition to fourteen sections of the association, forty-one national scientific societies met in Chicago and the official program of 112 pages exhibited the scientific productivity of the nation in the whole range of the natural and exact sciences. At the opening session on the evening of December 27, after the introduction of the president of the meeting, Dr. L. O. Howard, and greetings by the president of the University of Chicago, Dr. H. P. Judson, the retiring president, Dr. Simon Flexner, gave his address "Twenty-five Years of Bacteriology," which was listened to by a crowded audience with absorbed attention. on Two other general evening ses sions of popular interest were held. At one of these was given an illustrated lecture by Dr. R. F. Griggs, on the region of Mt. Katmai, Alaska, and the "Valley of Ten Thousand Smokes." The other general interest lecture was by Professor R. W. Wood, on high power fluorescence and phosphorescence, in connection with which he performed numerous ingenious experiments and demonstrations dealing with the study of these phenomena and of ultra-violet light. The sessions were held mainly in buildings of the University of Chicago, which furnished excellent facilities. The total registration was 2,412, which is the largest registration ever recorded for the association, and it must be remembered that many persons in attendance at the meeting failed to register, so that the correct number was much larger. The increase in scientific knowledge and interest among the general public is one of the most important functions of the association and the one which it has been most difficult to accomplish. The reports in the press vary from year to year, and at Chicago represented a fair average. Several of the more important papers, such as that of Professor Michelson on the application of interference methods to astronomical measurements, were fully reported, not only in Chicago but also in New York and other cities. The Science Service, definitely organized at Chicago for the wide-spread diffusion of current scientific information, will hereafter make possible adequate reports of scientific meetings. It was decided that the next meeting of the American Association will be Toronto, on Tuesday, Decem |