266 CLINICAL BACTERIOLOGY AND H/EMATOLOGY 



percentage of lymphocytes and the total number of leucocytes 

 in almost all infantile diseases, especially rickets and hooping- 

 cough. 



In adults a very high total count (100,000 or more) with a 

 very high percentag * of lymphocytes (up to 99-5 per cent.) 

 indicates lymphatic k icocythaemia. Smaller increases some- 

 times occur in other diseases. 



A relative diminution of the lymphocytes frequently occurs 

 as a result of the increase of other leucocytes, rarely as a true 

 absolute diminution. 



Large Hyaline Cells. An increase or decrease of these is 

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

 diagnosis. 



Polynuclear Leucocytes. This is the most common cell to 

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

 leucocytosis given on p. 251 it may be assumed that the in- 

 crease 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 poly- 

 nuclears it must be regarded as a bad sign. A relative in- 

 crease 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 glyco- 

 genic 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 



