The shape of the human red blood corpuscle

Abstract

In a paper published in 1909 1 I presented evidence in refutation of the new teaching 2 that the normal shape of the mammalian red blood-corpuscle is cup-form. This evidence included data derived from an examination of the capillaries in the omentum of an anesthetized cat, sections of variously fixed tissues, and hanging drop preparations of fresh blood. The latter, sealed and kept at body temperature, were thought to simulate closely actual conditions in the blood vessels of the living animal. The free central corpuscles of such a drop preparation are almost exclusively of the circular biconcave disc form. In view of all the evidence there seemed to be no escape from the conclusion that the biconcave disc-shape is the normal, the cup-shape the derived, form of the mammalian erythroplastid. But since opinion still remains divided on the point as to what is the original and normal shape—that is, whether cup or disc—additional evidence is demanded. Cogent confirmatory data accrue from observations of the corpuscles in the gelatin solution recently devised by Hogan 3 as a substitute for salt solutions for transfusion purposes in clinical cases calling for relief to a fall in blood pressure. The special point of advantage claimed for Hogan's normal-salt-gelatin mixture is that it has the colloidal constitution of blood plasma, and in consequence is not lost from the blood vessels through secretion and osmotic processes as salt solutions are supposed to escape.

The method of procedure in my investigation was to place the Hogan's solution 4 in an incubator at a temperature of 42'C. Hollow ground culture slides, cover slips, a pipette, and a needle were also kept in the same incubator. The excess above the normal body temperature was planned to compensate for the cooling incident to the frequent opening of the incubator and the transfer of the preparation for study to the microscope stage.