concern to the community at large than it is to the purchasers of shells or to the shellers themselves that the resources of a particular region should be conserved. It is a comparatively simple matter for the manufacturer to strip his plant and to remove his machinery to another locality with undepleted resources; it is an easy thing for the sheller, with his scant equipment in a house boat, to float down the river, looking to find another temporary home where his labors may be more profitable. It is the interest of the community that is threatened. The loss of a substantial industry affects the profits and the welfare of innumerable persons who may have known little of their indirect interest in a business in which they did not immediately participate. The communities most immediately affected are those of the river towns which, as a general rule, are too limited in their sources of fixed income.

From the standpoint of community economy, an unfortunate feature of the mussel fishery, as it has been pursued up to this time, has been its nomadic character. The policy everywhere has been to clean up the beds of a locality, or of a stream as a whole, and then to move to new regions. Temporary cutting plants, or "factories," have frequently been established in the vicinity of active shelling, to move subsequently as the local fishery passed away. Only the larger and more firmly established branch plants of the principal factories have maintained a fixed location.

It will be brought out later in this report that it does not appear possible to insure the best condition of the mussel beds, except by some plan of rotation; but it would be desirable and favorable to the interest of all for the mussel fishery to be a permanent and dependable feature of the industrial life of the broader communities, if not of particular restricted localities.

The perpetuation of the mussel resources may well receive the best consideration of every State concerned and of the National Government as well. It affects the welfare of thousands of shellers, of hundreds of river towns over the broad Mississippi-Missouri Basin, of manufacturers and laborers, east and west, and, it might be said, of every user of pearl buttons, which comprises practically the entire population of the country.

The Government and the States can accomplish the desired object by two principal means—artificial propagation and legislative protection. It is the province of the present paper to deal primarily [7]with the subject of protective measures, but it will be advisable to give first an abbreviated account of the conditions and possibilities of artificial propagation, especially as the results of propagation will be greater or less according to the degree of protection extended to the young mussels.

ARTIFICIAL PROPAGATION OF MUSSELS BY THE GOVERNMENT

ESTABLISHMENT OF PROPAGATION.

The Bureau of Fisheries has always maintained an active interest in the development of the fresh-water mussel fishery of America, which, in its importance and breadth of territory, is entirely unique in the world. As early as 1897 and 1898, the shell fishery being then only 4 or 5 years old, the Fish Commission undertook investigations relating to the various phases of the industry, and several reports were published dealing with the natural history of mussels, the shell and pearl fisheries, and the button industry. In a general report on the subject Dr. Hugh M. Smith then recommended measures for the protection of mussels. No action followed, and in consequence the scene of the most important fisheries has greatly shifted since that time.

Some years later there began a special investigation of the reproduction of mussels, which resulted in the methods of artificial propagation as developed by Prof. Lefevre and Prof. Curtis, of the University of Missouri, in association with the Bureau. The Government then established the Fairport Biological Station to engage in the propagation of mussels and the studies of mussel problems, besides exercising wider activities in fishery investigations. For a number of years field investigations relating to the distribution, habits, and conditions of life of the mussels have been prosecuted by the staff and associates of the Bureau throughout the Mississippi Basin.

For the first two years at the Fairport station mussel propagation was carried on in an experimental way, but beginning with 1912 the practical operations have been conducted upon as large a scale and over as wide a territory as the available resources permitted. During the past two years mussels have been propagated chiefly in the Mississippi River from Lake Pepin, in Minnesota, to New Boston, Ill.; in the Wabash River in Indiana, and in the White and Black Rivers of Arkansas. During the year ended June 30, 1913, about 150,000,000 glochidia, or young mussels, were put out, and in the first half of the present fiscal year that number is fully equaled. Such figures appear large. It is not difficult by the methods of propagation to handle considerable numbers of glochidia; indeed, it is necessary to work on an ample scale, for in mussel propagation, as in most forms of fish culture, what we can now do is to aid the young over the most [8]critical period in their life history, after which they must be left to continue the struggle for existence by their own efforts.

We therefore plan to work in such a way that, even with the liberal discount that nature will surely apply to our returns, there may be left a real measure of benefit gained without undue cost. Many of the young will be lost from falling upon unsuitable bottoms and from many other unfavorable conditions, such as confront every young mussel in nature with more or less frequency. We would like to remove all of the unfortunate conditions productive of loss, both to the mussels that we put out and to those that are propagated entirely by natural means; but this, of course, is not possible. There are, however, artificial conditions which do injury to the younger mussels, and it is both desirable and practicable to prevent such damage as far as can be done reasonably.

RESULTS DEPENDENT UPON PROTECTION.

In the regular fishery for mussels the beds are continually dragged over with rakes, tongs, crowfoot hooks, or dredges. It is inevitable that the young mussels will suffer to some extent from this process. It is quite unnecessary, however, for the "infant" mussels, many of them too small for any use at all and many more too small for any economical or proper use in manufacture, to be entirely removed from the beds. Mussels are thus uselessly destroyed that might be left to grow to a size at which they would be both commercially valuable and properly usable; meantime, too, they might take their natural part in the reproduction of the species.

Furthermore, it would be desirable to leave portions of the rivers entirely undisturbed by the operations of shelling during periods of some years. This would accomplish a double object—it would leave the best conditions for the natural reproduction of the remnant of the old stock and for the growth of the young mussels and at the same time it would create a series of reserves in which artificial propagation could be carried on with the best conditions for maximum results. In such closed regions the young mussels would have to contend against only the normal unfavorable conditions which all mussels have ever had to withstand, without an added toll of destruction being taken by the direct and indirect effect of the operations of men.

The simple "closing" of a depleted region, if the exhaustion has not proceeded too far, may be expected to lead to sure betterment, and even in time, if the closure were for a very long period, to a