Size and Morphology of the Elementary Bodies of the Psittacosis-Lymphogranuloma Group of Viruses

Abstract

Several investigators (1–7) have shown that the growth of the pathogenic agents of the psittacosis-lymphogranuloma group of viruses in the yolk-sac of embryonated hens' eggs is associated with the formation of minute, round structures known as elementary bodies. The accumulated evidence indicates that these minute bodies represent the viral particles themselves. In addition to the elementary bodies, larger structures measuring about one micron in diameter and possessing the same tinctorial properties as those of the elementary bodies frequently are seen in stained smears of infected yolk-sacs. It has been suggested that these larger structures represent developmental forms in the life-cycle of the elementary bodies (7, 8). Since elementary bodies are only a fraction of a micron in their dimensions, it is difficult to ascertain any definite details of their morphology with the highest magnifications obtainable with the ordinary microscope.