230 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



Large Hyaline Cells. — An increase or decrease of these is 

 occasionally observed, but so erratically that it is of no use in 

 diagnosis. 



Polymdeav Leucocytes. — This is the most common cell to undergo 

 increase, so much so that in the list of causes of leucocytosis 

 given on p. 215 it may be assumed that the increase is due partly 

 or entirely to an increase of polynuclears, unless the opposite is 

 stated here. 



One special case needs a reference. In severe sepsis with a 

 normal or diminished polynuclear count it is usual for the 

 polynuclears to be relatively increased, just as they are when 

 the total count is raised. This is very important in diagnosis, 

 for in cases where sepsis is suspected a normal leucocyte count 

 must always be followed by a differential count, and if there is a 

 relative increase {e.g., 85 per cent, or more) of polynuclears it must 

 be regarded as a bad sign. A relative increase of polynuclears 

 with a normal or moderately raised total count may also occur in 

 malignant disease. 



A form of degeneration of the polynuclears requires notice, as 

 it is of some practical value. This is the iodine or glycogenic 

 reaction. To test for it make a film in the ordinary way, dry 

 and mount it without fixation in the following mixture : 



Iodine i part. 



Iodide of potassium - - 3 parts. 



Saturated watery solution of gum acacia 100 parts. 



This should not be used more than a fortnight after it has been 

 made. (A simpler but equally good method is to expose the film 

 to the fumes of solid iodine for a few hours. This can be done by 

 fixing the film (without previous treatment of any sort) at the top 

 of a wide-mouthed bottle containing the substance ; it is then 

 mounted in oil or balsam.) Allow it to act for a quarter of an 

 hour or more, then examine with a y\^-inch lens in a white light 

 — daylight if possible. In cases where the reaction is present 

 a variable number of the polynuclears will be found to contain 

 granules or masses of a reddish-brown or mahogany colour ; 

 sometimes there are large masses, and sometimes almost the 

 whole of the protoplasm appears brown. 



The importance of this reaction is that it usually occurs, and 

 is indeed very marked, in the cases of severe sepsis in which 

 there is no increase of the total leucocyte count (see p. 217), as 

 well as in suppuration. It occurs in other conditions, such as 



