SPECIAL METHODS. 21$ 



On the other hand, it has been shown by Altmann (I) that 

 bodies of definite reactions may be quite generally recog- 

 nized in the cytoplasm of animal cells, which this author 

 terms granula and regards as the elementary organisms of 

 the cell. Altmann used, for the demonstration of these 

 granula, chiefly a fixing mixture of osmic acid and potassium 

 bichromate and the acid fuchsin staining method A, de- 

 scribed in 345. 



374. How far the cytoplasm of plant-cells possesses a sim- 

 ilar granula-structure cannot at present be said. The writ- 

 er's investigations on this point have not yet reached any 

 conclusive results. But, by the aid of Altmann's methods,, 

 it can be shown that certain bodies are widely distributed in 

 the cytoplasm of the cells of the assimilating tissue, which 

 correspond in many respects with Altmann's granula and 

 have been termed at first simply granula (cf. Zimmermann^ 



ii, 38)- 



These are always colorless and are mostly little spheres,, 

 which have, at most, about the size of the nucleoli, in adult 

 cells (cf. Fig. 48, g). Their chemical relations indicate that 

 they consist of protein-like substances. 



375. F 'or fixing the granula a concentrated alcoholic solu- 

 tion of corrosive sublimate 



or of picric acid may be 

 used (cf. 310 and 303). 

 Very good results have 

 been obtained also with 

 dilute nitric acid, and I 

 used in this case a solution 



Containing, in O7 Volumes FIG. 48.- A cell from the lowest mesopHyll layer 



of Tra.desca.ntia- albijlora.^ from a prepara- 



of water, three volumes of tlon fixed wilh alcoholic picric acid and 



stained by Altmann's acid fuchsin method, c. 

 Chemically pure nitric acid chloroplasts; *, nucleus; f , granula. 



of specific gravity 1.3, which therefore contained about 1.5$ 

 of HNO S . I allowed this solution to act for 24 hours, and 

 then washed the objects in running water for 24 hours. 



For staining the granula I formerly used almost exclusively 

 Altmann's acid fuchsin method ( 345), but have lately con- 

 vinced myself that the other acid fuchsin methods ( 346 



