32 



Leukccniia : Mixed leucocytosis. This is probablj' the most 

 interesting of all the changes in the blood. 



Here we have a profound alteration in the number and 

 quality of the corpuscular elements. The blood is so charged 

 with white cells that, on allowing it to stand a few minutes, a 

 thick, white scum rises to the surface, having the appearance 

 of matter or pus. In fact, at one time it was looked upon as 

 pus in the blood. 



The number of the red cells is greatlj- diminished, there 

 being sometimes only 1 or 2 millions instead of 5 to the 

 cubic millimeter. 



One finds many red cells with nuclei deeply stained by 

 methylene blue or haematoxylin. Some of these show mitosis. 



On the other hand, the leucocytes are enormously 

 increased, the number reaching 400,000 to 800,000. I n fact, they 

 are sometimes as numerous as the reds instead of the normal 

 ratio of 1 to 500 or 700. This leucocytosis is of the mixed 

 type and, moreover, contains other elements not normally 

 found in the blood. 



There are certain specific changes in the composition of 

 the white cells which make it possible to give a definite 

 diagnosis from the examination of a blood film, irrespective of 

 the leucocytosis. 



First — all three types of granulated cells — the finely 

 granular and coarsely granular eosinophil and the mast cells 

 are increased. 



Second, in addition to the polynuclear cells, their early 

 stage, the large mononuclear granular corpuscle or myelocyte 

 is found in the blood. 



Third, atypical cell forms appear, e.g., dwarf forms of all 

 kinds of white corpuscles. 



Fourth, numerous nucleated red corpuscles. 



I have placed several slides under the microscopes, 

 showing these points. 



I wish to emphasise that in these cases we are not simply 

 dealing with a very marked leucocytosis of the ordinary type, 

 such as is found in pneumonia, &c., and made up of the 

 polymorphonuclear cells. 



