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The effect of a variety of synthetic peptides on rat mast cells was investigated. Peptides with two or more basic groups were active histamine releasers, while eledoisin, angiotensin I and II, glucagon, and fibrinOpeptide A had slight or no activity. The activity of bradykinin analogues increased with the chain length. Des-arginine derivatives of bradykinin did not release histamine. The most potent histamine liberators were substance P and Polisteskinin; the activity of the latter one approached that of 48/80. Because histamine could be released by the kinin peptides without disruption of the mast cell membrane, these agents like 48/80, probably stimulate exocytosis of mast cell granules.

The coincidence of the blastopore with the anus in the Newt has already been observed by Mr. Sedgwick.1 His assertion was, he says, based only upon surface views. He therefore suggested to me that I should attempt to verify it by cutting sections of the embryos, and my results confirm what he has stated.2

The effect of radiant energy upon the metabolism of small doses of Fe in the nutritional anemia of the rat seems to have been little studied. Foster1produced anemia in rats by milk feeding and observed the effect of radiant energy in preventing and curing this type of anemia. There was a slight but definite effect in increasing the hemoglobin and the number, size and saturation of the red cells.We have made the following studies upon the effect of radiant energy upon both the prevention and cure of nutritional anemia in the rat.Preventive Studies.Young rats at weaning were fed upon whole milk. Daily doses of pure Fe from 0.05 to 0.30 mg. were given, with and without 3/4 hour ultraviolet irradiation of the rat daily, with the General Electric Sunlight Mazda Lamp, Type S-I, at a distance of 4 feet. This lamp has recently been described by Carter.2Weekly estimations of hemoglobin and red cell counts were made by the technique described by Beard and Myers.8With milk alone, milk plus irradiation, irradiated milk, and milk plus 0.05 mg. Fe daily the anemia became progressively worse. There was a striking effect of irradiation on red cell recovery with both 0.05 and 0.10 mg. Fe daily, namely, a drop of 41 and 0.6% on these doses of iron may be compared to an increaseof 33 and 50% when 3/4 hour irradiation was given. The anemia was prevented by daily doses of Fe from 0.15 to 0.30 mg. These doses with irradiation were also much more effective in preventing the anemia than were these doses of Fe alone, with the exception of the 0.25 mg. dose. Irradiated milk with 0.30 mg. Fe daily gave a much more striking increase in both cells and hemoglobin than any other type of therapy used in this study. These results are given in Table I.A polycythemia occurred in 4 animals on doses of Fe alone and in 12 animals on Fe and irradiation.