Little is known concerning the function of the eosinophil white blood cell. Its origin and life cycle are still a matter of controversy. In man, the eosinophil normally constitutes from 1 to 4 per cent of the circulating leukocytes, and an increase is of diagnostic value in several diseases. However, it is well known that normal guinea-pigs may have as many as 30 per cent eosinophils. Brown1 first recognized the diagnostic importance of eosinophilia in trichinosis. He recognized, however, that in severe infections the circulating eosinophils may be either absent or few.
Opie2 produced in normal guinea-pigs with marked eosinophilia, infections with Bacillus tuberculosis, Bacillus pyocyaneus, Bacillus mucosus-capsulatus and Streptococcus pyogenes. During the course of the infection, the eosinophils disappeared not only from the blood but from the tissues. Coincident with their disappearance from the blood, there was an accumulation of eosinophils near the site of inoculation. Canon