Retardation is a necessity and a convenience in the production of maggots for surgical use. It is an essential step in the process because during the tests of sterility, which are made on all maggots, the growth of the maggots must be restrained; otherwise they become too large for use in wounds. It is also essential during long distance shipments. Retardation is a convenience, as it permits the holding over of maggots not needed at the time.
Low temperature is at present the chief means used to produce retardation, but a recent investigation1 has shown this method to be injurious, chiefly because it destroys a large percentage of the maggots. In view of the need of a more efficient method, experiments were conducted on retardation by nutritional means.
The maggots used were those of the species Lucilia sericata; they were reared under the usual aseptic technic.2 All cultures