The average protein content of the soy bean is 36.5 per cent. while that of the soy bean cake is about 41 per cent. The protein of the soy bean has all the amino acids necessary for nutrition and it is claimed to be as valuable as the casein of milk. The proteins of the soy bean, unlike those of other leguminous plants thus far investigated, were found, by Osborne and Mendel, to be adequate for promoting normal growth. In addition to the high protein content, the soy bean is found to contain an adequate amount of water-soluble vitamine and some essential fat-soluble vitamine. These factors combined with low cost make the soy bean of unique significance as a food.In working with proteolytic enzymes of fungi, the author found some organisms that are able to develop active enzymes which readily hydrolize the soy bean proteins and make them soluble. By using the ground soy bean cake as a substratum for the growth of the proteolytic fungus, then, at the end of the proper incubation period, which is usually abo...