EXPLANATION OF PLATES 



All figures are drawn with Zeiss camera under Zeiss \K oil-immersion objective 

 and Zeiss compensating ocular 18, at the distance of 250 mm. ; tube length, 160 

 mm. By reproduction, figures 36 to 120 were reduced to four-fifths of the original. 



PLATE 1 



EXPLANATION OF FIGURES 



1 to 35 Nuclei of the pancreatic cells of Rana temporaria. 

 1 to 6 Sublimate; iron-haematoxylin. 



7 Alcohol; iron-haematoxylin. 



8 and 9 Formalin; figure 8, Altmann stain; figure 9, iron-haematoxylin. 



10 to 13 Sublimate-acetic acid; figures 10, 11, Benda stain; figure 12, iron- 

 haematoxylin; figure 13, alum-haematoxylin. 



14 to 16 Sublimate-formalin; figure 14, Altmann stain; figures 15 and 16, 

 iron-haematoxylin. 



17 to 20 Champy's method for mitochondria; figures 17 and 18, Benda stain; 

 figure 19, iron-haematoxylin; figure 20, safranin. 



21 Potassium bichromate-formalin; Altmann stain. 



22 and 23 Regaud's bichromate-formalin-acetic mixture; figure 22, iron- 

 haematoxylin; figure 23, alum-haematoxylin. 



24 Osmium-sublimate; Altmann stain. 



25 Fixed and stained after Benda. 



26 and 27 Meves' fluid; figure 26, Benda stain; figure 28, iron-haematoxylin. 



28 Zenker's fluid; alum-haematoxylin. 



29 and 30 Trichloracetic acid; figure 29, Altmann stain; figure 30, iron- 

 haematoxylin. 



31 to 35 Cajal's photographic method. 



41 : 



