The problem of rearing caddice fly larvae and correlating the immature and adult stages of the Minnesota species has been a graduate student project in the Division of Entomology and Economic Zoology at the University of Minnesota for six or seven years. Mr. Winston Elkins was the first to work on the problem and published his results in 1936. Mr. Donald Denning is following up the work of Mr. Elkins and published his first results in 1937. Some six or seven years ago caddice fly larvae with a log-cabin type of case were noticed in the temporary ponds in the forest at Itasca Park, Minnesota. Tremendous numbers of these cases were present in the ponds. Owing to the fact that none of the interested persons could spend any time at Itasca Park during the several weeks at the period when the larvae transformed to pupae and later to adults no attempt was made to rear the species through at Itasca Park or to make observations of it in the temporary ponds. Numerous attempts were made to get these log-cabin cases containing larvae to our St. Paul laboratory and to rear the larvae to the adult stage, but in every instance they either died while being transported from Itasca Park or shortly after reaching the laboratory. In transporting these larvae within their cases the latter were placed in pint jars containing water from the ponds and brought by automobile to St. Paul. Care was taken not to crowd the cases in the jars and thus bring about an oxygen deficiency in the water. The distance from Itasca Park to St. Paul is two hundred and twenty-five miles and requires a drive of from five to eight hours.