“…On this basis it would appear that soybean oil meal is not essential for the production of this deficiency. These results are in agreement with the observations of McGinnis and Carver (1947) in studies of a growth factor in fish meal. An evaluation of the tests indicates that the response obtained is very consistent and of such a nature that it may be suitably adapted to a biological assay for the unidentified factor(s) which is present in fish solubles.…”