Tlic rrl.il Kills ol iiiiloclioiiilria ami nllur c \ l(»iilasiiiir conslitiu-iits etc. 49^ 



the- siiiootli even outliiics of tlic ("iiiiils ;is inciitiniicd lieretoforf. Tlifv 

 often appcjir lo form j)c!culiai' riiiiis ;iiiil cicmthis wliicli SL'eiii to Im; 

 isolated froiii tlie rest of the reticiiliiin. 'IIh- npiiarent continuity of 

 tlic iiieslios (Icpciids, hii'udy. ii|i(iii Ilo- tliickiicN- dt the section. Like 

 the clear canals, this IJiiinciiiict/ ol l\n|i>ch caw \>r shnwn tu he 

 independent of both the Xissl substance and the mitochondria. 8on»e 

 sections of this material were passed down tliiouL!Ìi toluol and g-i-aded 

 alcohols to distilled water, and were countcrstuiucd in a saturated 

 aqueous solution of safranin, differentiated in 95°/o alcohol, dehydrated, 

 cleared in toluol, and mounted in l)alsani. The Xissl substance was 

 thus stained red between the black meshes of the i-eticulum which 

 retained its original character and configuration (fig. 14). Tho mito- 

 chondria may likewise be demonstrated in the same cell with the 

 reticular apparatus. To accomplish this the acid fuchsin-toluidin blue 

 method of Bensley is employed. Specimens are passed down to 

 distilled water, are treated with the iiotassinm pt^inanganate and oxalic 

 acid solutions in order to remove the osmium. They are Then washcil 

 in distilled water, stained with acid fuchsin, and differentiated in 

 toluidin blue. The niitochondi-ia become stained red, the Nissl sub- 

 stance blue, and the clear canals winding in and out between them 

 represent the reticular apparatus which has been bleached by the 

 action of the potassium permanganate and oxalic acid. A few neuro- 

 fibrils may be seen stained brown in the axone hillock. The reticulai- 

 apparatus may be retained in its original form in the same cell in 

 which the mitochondria and Mssl substance are stained by this 

 method if the bleaching is omitted; in this case, however, the cells 

 are somewhat blackened and opaque due to the retention of the osmium. 

 Compare figures 16, 17. 25, 26 and 27 with Kopsch. 1002, fig. 1. 



Von Bergen (1904, p. 514Ì was, I believe, the first to employ 

 iron hematoxylin as a positive dye for the reticular apparatus. Spec- 

 imens fixed in potassium bichromate were stained with iron hema- 

 toxylin according to Heidenhain. In them the reticular apparatus 

 was stained deep black and appeared in all respects identical with the 

 network seen in the Kopsch preparations. 



Bensley (1910) has discussed the nature of the canalicular appa- 



