19 



shown by its less intense staining. They also 

 present indentations giving a partly bi-lobed 

 appearance. 



(iii) Tlie area of protoplasm surrounding the 

 nucleus is considerable. It is clear, and contains 

 at most a few scattered granules (Romanowsky 

 stain). The only difficulty will be found to arise 

 in the case of a comparatively small number of 

 ' intermediate ' and ' transitional leucocytes.' 



Intermediate Leucocytes (Fig. 2). — These are 

 forms intermediate between the large and small 

 mononuclear forms. They are usually classed 

 along with the large forms, the characteristics of 

 which they generally more nearly approach. 



Transitional Leucocytes (Fig 2). — These are 

 very characteristic, and when seen will be at 

 once recognized. In shape, the nucleus approaches 

 that of the polymorphonuclear forms, being trident- 

 shaped or S-shaped. In consistence, however, it 

 is obviously related to the nuclei of the large 

 mononuclear cells. As a rule these cells are small 

 in number, and from their close resemblance to 

 the Ifirge mononuclears may be included with 

 these. 



Eosinophil Leucocytes (Fig 2). — The large 

 granules with which these are packed suffice to 

 distinguish them. The granules are stained pink 

 or blue (peripherally) by Romanowsky. The 

 nucleus in the eosinophil cells is frequently 

 characteristic, consisting of two spherical portions 

 united by a thin strand of nuclear material ; it is 

 really of the polymorphonuclear type. 



Mast Leucocytes (Fig. 2, M). — These, in a film 

 stained by Romanowsky, are cells crowded with 

 granules stained deep blue or nearly black. 



