THE JOURNAL OF PHARMACOLOGY. ! 27 



Plate I. 4 reresents normal blood. Notice the red blood corpuscles are all 



4 Dr. Walker's paper was illustrated by colored charts reproduced from 

 stained films. 



about the same shape, size and color. Each has a light spot in the centre, 

 which is called the delle. This is due to the corpuscle heing biscuit-shaped 

 and not so thick in the centre. 



Plate II. is primary pernicious anemia. Notice the diminution in num- 

 ber and amount of hemoglobin in some corpuscles, while others appear 

 entirely filled with bemoglobin. There is a marked difference in size 

 and shape. Some are several times the size of a normal red blood cor- 

 puscle, as seen in Plate I., another much smaller, and others have various 

 shapes. The number of corpuscles, as you see, is diminished, but many are 

 well filled with hemoglobin, especially the larger ones; consequently the 

 amount of hemoglobin estimated with a hemometer would be greater than 

 with the same number of normal corpuscles, and we would have a high 

 color-index, which we have referred to under the discussion of color-index. 



We can now take up the nomenclature of these forms. The normal 

 red blood corpuscles are called erythrocytes, the larger ones megalocytes, 

 the various shaped- ones poikilocytes, and the small ones microcytes. Ehr- 

 lich calls both poikilocytes and microcytes schistocytes, for he says they 

 are parts of an erythrocyte. They generally have a delle, which he ac- 

 counts for by saying that the contents being hemoglobin its form is due 

 to the discoplasm, and a schistocyte being a fragment of an erythrocyte 

 it is able, without its discoplasm, to form a delle. In man erythrocytes 

 have no nucled, but we find them nucleated in the embryo. So we have 

 erythroblasts, that is, nucleated red blood corpuscles. And following the 

 above nomenclature, normoblasts, megaloblasts, microblasts and poikilo- 

 blasts. These are all pathological conditions of the cell, and we find, 

 -especially in leukemia, the nucleus undergoing division either by con- 

 strictions or in the various stages of karyokinesis. 



The leucocytes have had more study devoted to them than any other 

 constituent of the blood. Many attempts have been made to obtain a 

 satisfactory classification. We will briefly review these classifications, so 

 we may better understand the terms in use and their significance. The 

 classification is generally a mixture of three methods, namely, according 

 to supposed origin, according to form of nucleus, and according to the 

 micro-chemic reactions of the granular matter in the cells. In classifying 

 the leucocytes according to their origin (lymphocytes, splenocytes, myelo- 

 cytes, etc.), we are very much in the dark. Many of the theories regard- 

 ing their supposed origin are very interesting. Time will not permit us 

 to discuss them, so we will simply accept these names for certain forms 

 of leucocytes. Classification according to the form of nucleus gives us 



