Abstract
Blood and plasma smears of mice inoculated with two leukemic lines were studied under the electron microscope.
In 15 mice of the AKR strain and in two C58 mice inoculated with the Hch leukemia line of the Instituto de Biología of Chile (372 to 382 transfers), dense submicroscopic particles were found in the blood plasma. In some cases isolated particles or clumps of them were found adsorbed on the red cell membranes. The particle size ranged between 19 and 58 mµ, with a large peak at 38 mµ. The survival time of the inoculated animals was of 5 days and the submicroscopic particles were constantly found between the 3rd and 5th day.
Similar dense submicroscopic particles were found in blood plasma smears of three C58 mice at the 16th day after inoculation with the Ich leukemia line (86th transfer).
The probable significance of these particles is discussed on the basis of the literature regarding the etiology of mouse leukemia.
