Comparable groups of baby chicks, given meat meal supplements from different sources, did not grow at the same rate, even though the diets were balanced to the same level of protein. The incidence of nutritional para lysis (curled toes) varied also with the meal used. As a protein supplement fishmeal was very much inferior to meatmeal and also to crayfish meal and whale meal. Growth promoting value of fishmeal was greatly enhanced, however, when it was combined with a small amount of brewer's yeast or casein. This improvement was most marked in the case of casein, but yeast apparently supplied some factor which prevented nutritional paralysis.