SS POPULAR SCIENCE MONTHLY
can be with the water removed. Hence an extended and careful study of the crops available for culture in such tracts becomes a pressing necessity. Such a study will of necessity involve years of investigation, both of the practises in countries where some such systems exist and of possibilities under our own conditions of available crops, markets, machiner}', etc.
A short resume, however, of some of the crops which already have some claim to notice and those which give promise of availability will help to show the possibility and practicability of such a system.
Among the plant crops which may be mentioned are water cress, which is already an article of considerable commercial value, but prob- ably much less used in this country than elsewhere and doubtless much less than if the supply were increased. Methods of its culture are, of course, well known and would be simply a matter of adaptation to particular areas. The cranberry is also a well-known crop, adapted to bog or swamp conditions and for which there is unlimited demand.
Some of the marsh grasses, cat tails, rushes and other plants make a most abundant growth, and in association with other crops could no doubt be cultivated to good advantage. The basket willows are of great value and are used extensively in the manufacture of baskets, an indus- try which is capable of much expansion. The pond lily surely offers an opportunity for a most valuable aquatic crop, if systematically culti- vated and harvested, especially in the vicinity of large cities and popular excursion resorts.
We may mention, also, the development of the industry, based on the slough-grasses of the northwest, including the manufacture of bind- ing twine, mattings or carpetings and furniture. This utilizes an extensive area of wet land, not available for other crops, and which, if retained for this crop, doubtless could be utilized also in the culture of some other more distinctly aquatic crop. Other fiber plants are a possibility.
Of animal crops which are already known, fish culture is the most extended, but in general this is not reduced to a systematic farming basis. I can recall the furore created some twenty-five or thirty years ago, in connection with the introduction and proposed production of carp, but so far the carp industry in this country is mainly confined to that grown without attention, and gathered indiscriminately by fishermen without reference to any private rights. The market for this fish has, however, greatly increased and in centers where there is a large European population, as in New York City or Chicago, im- mense quantities are sold, and it is claimed that these people prefer carp to other fish which are greater favorites with American tastes. Under other names carp are sold to a considerable extent in our markets and, under such disguises as " smoked sturgeon," may pass as a distinct