138 THE AMERICAN MONTHLY [May 
Terminology of the Study of Blood Normal, and Abnormal. 
HARRY D. OBERT, M. D. 
The blood consists of a liquid basis or plasma, in which , 
are found two great varieties of cells, the red and white. 
The red ones are termed erythrocytes and the white ones 
leucocytes. The red cells are bi-concave discs, dark at the 
edge and with a clear or bright spot in the centre due to 
their bi-concavity. When this spot shows very distinct- 
ly a pathological state exists which we term endo-globu- 
lar degeneration. Thereis no nucleus in the red cells. 
The white ones are nucleated in various manners, accord- 
ing to their stageofdevelopment. In addition to the cor- 
puscles, there exists the so-called blood plates. Blood 
plasma when obtained free from corpuscles is perfectly 
colorless in thin layers. The red color of the blood is not 
due therefore to the blood plasma, but is caused by the 
mass of corpuscles held in suspension. | 
The blood leucocytes which are by far the most inter- 
esting part of the blood to study, are divided up in dif- 
ferent classes, depending upon their stage of development. 
The function of these leucocytes has been the subject of 
numerous investigations, particularly in connection with 
blood diseases, but it cannot be said that we possess any 
positive information as to the normal function of these 
cells. These cells are not all the same, histologically. 
Erlich’s classification divides them into three groups ; (1) 
Oxyphiles or Eosinophiles, or those which stain with an 
acid aniline dye, the acid portion of the dye acting as the 
stain. (2) Basophiles, those staining with a basic dye. 
(3) Neutrophiles, those staining with a neutral dye. These 
white cells are nucleated, with one, two or more nuclei 
which change their type and may become the so called 
transitional, the terms then, being mono-nuclear tran- 
sitional and poly-nuclear. Normally the reaction of the 
blood is alkaline owing mainly to the alkaline salts and 
