1. To preserve fish waters, especially those inland, as nearly as possible in their normal condition. 2. To prohibit wasteful or immoderate fishing. 3. To employ the art of fish breeding. _a._ To aid in maintaining a natural supply; _b._ To repair the effects of past improvidence, and _c._ To increase the supply beyond its natural limits, rapidly enough to meet the necessities of a constantly increasing population. The preservation of normal conditions in inland waters is comparatively simple. A reasonable system of forestry and water purification is all that is required, and this is needed not only by the fish in the streams, but by the people living on the banks. It has been shown that a river which is too foul for fish to live in is not fit to flow near the habitations of man. Obstructions, such as dams, may, in most instances, be overcome by fish ladders. The salmon has profited much by these devices in Europe, and the immense dams in American rivers will doubtless be passable, even for shad and alewives, if the new system of fish-way construction devised by Col. McDonald, and now being applied on the Savannah, James, and Potomac, and other large rivers, fulfills its present promises of success. Up to the present time, however, although much ingenuity and expense have been lavished upon fish-ways by the various state fish commissions of this country, there has been little practical outcome from their use. Our dams are too high, and the shad and alewives, which we are especially desirous to carry over these obstructions, do not seem to take kindly to the narrow, tortuous defiles of the fish ladders.