226 RALPH DOUGALL LILLIE 



so. Such granules are very fine, rounded, discrete, and stain 

 purplish pink. In these cases the cytoplasm is colorless. The 

 staining reactions of these granules will be further treated later. 



Transitions from large lymphocytes to special cells are readily 

 found. First the nucleus becomes slightly indented, then sausage 

 shaped, the nucleolus loses its differential stain and form and 

 blends with the chromatin, then a pink spot appears in the blue 

 cytoplasm (eosin-azure II) opposite the concavity of the nucleus. 

 Or the change of stain may be more diffuse and almost simul- 

 taneous throughout the whole cytoplasm. The chromatin 

 becomes more abundant and arranged along the nuclear mem- 

 brane, which is now more evident. 



One of these cells was seen in karyorrhexis. Its eosinophil 

 cytoplasm was non-granular and contained a horseshoe-shaped 

 nucleus whose chromatin was collected into numerous round, 

 strongly basophil granules within the nuclear membrane, except 

 at the tip of one lobe, where they were escaping into the cyto- 

 plasm. The karyoplasm itself was clear and colorless. Mitotic 

 figures are not rare in the special cells. 



Since it is usually stated in the literature that the special 

 leucocytes of the Amphibia are non-granular or have at most 

 only an azurophil granulation, I thought it worth while to in- 

 vestigate further the character of the fine granulation described 

 above. It may be noted here that in air-dried films of adult 

 blood and bone marrow of Bufo halophilus all the special leu- 

 cocytes show a fine purplish-pink granulation on a clear karyo- 

 plasm when stained with Wright's stain in the customary 

 manner. 



In order to eliminate as far as possible variations due to age 

 or differences in technique, sections of the mesonephros of a 

 single larva of 19-mm. body length were used for the following 

 series of staining reactions. All the stains used were differ- 

 entiated in 9G per cent alcohol, except the thionin which was 

 differentiated in absolute alcohol and cleared in xylene. The 

 dilute Wright's and Jenner's stains mentioned were diluted to 

 the same color tint as eosin-azure II— 1 : 10 : 1 (Maximow, '09 c). 



