A comparative histological and physiological study on the digestive systems of two insects, a carnivorous insect and a sap-feeding one, together with a detailed study on the digestive enzymes, food needs and secretions of the salivary glands of each insect. A detailed study of chemo-coloration of insects. A detailed histological and physiological study of the central and the anatomic nervous systems of insects and their roles in physiology, especially in growth, reproduction and protein synthesis. A detailed histological study of insect blood cells. A physiological study of the blood volume in insects and the various methods used in measuring it. An experimental physiological study of metamor-phosis in insects. A detailed study of the physiology of respiration in insects.