364 S. SAGUCHI 



B. Mitochondrial apparatus 



1. Technique. For the fixation of mitochondria I used 

 Zenker's, osmium-sublimate, Flemming's, bichromate-formalin, 

 bichromate - osmium - formalin, bichromate - osmium - sublimate, 

 Meves'-formalin (without acetic acid) and Maximow's mixture, 

 especially those advised by various investigators for mitochon- 

 dria: Meves', Benda's, Altmann's, Champy's, Kolster's fluid, etc. 

 Sections were cut from 2 ^ to 5 n in thickness and stained mainly 

 with Heidenhain's iron-haematoxylin, Altmann's acid fuchsin, 

 and Benda's crystal-violet. 



Generally speaking, the fixatives containing a great amount of 

 acetic acid, e.g., sublimate-acetic, Zenker's, Flemming's, etc., fix 

 the mitochondria only in cells of the superficial layer. In the 

 fixatives which contain a small amount of that reagent, e.g., 

 Benda's, Meves', etc., the mitochondria in the deeper portion 

 of the piece are well preserved; but there is no constancy in the 

 results with these fixatives, their action being often limited to the 

 more superficial region of the piece. The mixtures which pre- 

 serve the mitochondria in a fairly satisfactory manner throughout 

 the piece are osmic acid, osmium-sublimate, Altmann's bichro- 

 mate-osmium-sublimate, Maximow's fluid, etc., all of which are 

 without acetic acid. Of these, the bichromate-osmium-subli- 

 mate mixture works much better, for it not only preserves both 

 cytoplasm and mitochondria in equally good manner, but also 

 is adapted for either of the mitochondria stains above referred to. 



In the following paragraphs I will try to discuss the action of 

 the reagents commonly used for the preservation of mitochondria. 



a. Acetic acid. That acetic acid dissolves out or destroys 

 mitochondrial substance is a well-known fact, but it seems that 

 this does not necessarily occur when employed in combination 

 with other reagents. Fixed in mixtures which contain a large 

 amount of acetic acid, such as sublimate-acetic, Zenker's or 

 Flemming's fluid, both the cytoplasm of the superficial layer of 

 the piece and the mitochondria in it are preserved in a satisfac- 

 tory manner. This is perhaps due to the rapid action of the 

 reagents combined with acetic acid, the fixation taking place 



