EOSINOPHILIA OCCURRING DURING THE ADMINISTRATION OF ACTH

The eosinophil cells of the blood have been known since Ehrlich, in 1888, introduced differential staining. Eosinophil granulocytes are formed mainly in the bone marrow, and there is probably no relationship between the so-called tissue eosinophilia and eosinophilia in the blood. The physiological variations in the number of circulating eosinophils may be said to have been elucidated, and so are the variations occurring in the eosinophil count in the course of most diseases. On the other hand, little is known about the significance of the eosinophil granules. Although we are in a position to enumerate conditions usually accompanied by eosinopenia and others which have until recently attracted so much attention and are usually accompanied by eosinophilia in the blood, little is known about the regulation of the number of circulating eosinophils. The chemical composition of eosinophilic granules and their function are still unknown. Although a special function can probably be