366 S. SAGUCHI 



d. Chromic acid and potassium bichromate have been fre- 

 quently used for the fixation of mitochondria. So far as can be 

 recognized from my own experience, these reagents, used singly, 

 could not preserve mitochondria in any satisfactory manner. 

 On the other hand, it can scarcely be said that the presence 

 of these reagents in fixing mixtures is absolutely necessary to 

 the fixation of the mitochondrial substance; for, even in such 

 fixatives as osmic acid, formalin, osmium-sublimate, etc., which 

 contain no chrom-salts, mitochondria are well preserved. But 

 there seems to be little doubt that their presence in fixatives 

 favors the fixing and staining of mitochondria; Benda's Tost- 

 chromierung' will answer this purpose. 



e. Sublimate is not essential to the preservation of mitochon- 

 dria; since, however, this reagent fixes the cytoplasm both rapidly 

 and evenly, good results can be obtained when applied in combi- 

 nation with other reagents, e.g., bichromate-osmium-sublimate, 

 Maximow's fluid, etc. 



It will be seen from the above account that the reagents which, 

 used singly, afford fairly satisfactory results for fixing and stain- 

 ing mitochondria, are osmic acid and formalin, and that chromic 

 acid, potassium bichromate or sublimate alone do not have such 

 action. The combination of reagents to prepare fixatives for 

 mitochondria can be seen from the following diagram: 



osmic acid— —chronic acid or 



potassium bichromate 



formalin sublimate 



It is shown in this diagram, on the one hand, that fixatives 

 can be prepared by combination of two, three or four reagents, 

 which are connected by lines with each other; and, on the other, 

 that osmic acid or formalin alone can also be employed as a fix- 

 ative for mitochondria; acetic acid may either be added to the 

 fixatives or omitted. 



2. Shape, structure, and position. As described by Schultze 

 ('11), Levi ('12), and others, the mitochondria in the acinus cells 

 of the pancreas, in fixed and stained preparations, appear as rods 



