The occurrence of an unidentified chick growth factor(s) was reported in casein and liver meal by Johnson et al. (1942). Subsequently, other workers have reported that dried skimmilk, liver meal, whey solubles, distillers’ dried solubles, meat scraps, fish by-products, cow manure and hen feces also contain an unidentified factor for chick growth. Heuser and Norris (1944) reported that the addition of 2 percent of white fish meal to a ration, deriving its supplementary protein chiefly from soybean oil meal, resulted in a marked increase in growth and feed efficiency of chicks up to eight weeks of age. The rations used by Heuser and Norris together with the results are given in Table 1.In order to determine the amount of known B-complex vitamins supplied by such a small addition of animal protein material, laboratory analyses were made of the basal ration and the ration which included 2 percent of white .