Method for Demonstration of the Golgi Apparatus. 161 



and arrangement, are to be considered as mitochondria. This was, 

 in a way, to be expected, as in uranium nitrate preparations there 

 also appear sometimes well-stained mitochondria ; and Perroncito 

 has shown that similar results can be obtained by Golgi' sarsenious 

 acid method, if the fixing solution is made to act for some hours 

 at 45-50° C. The same happens almost constantly in the case 

 of my cobalt nitrate modification if the fixation is prolonged 

 to 18-24 hours at room temperature, or takes place with fluid 

 previously warmed and kept at 36-37° C. for a few hours as 

 explained above. An almost constant staining of both mitochondria 

 and internal apparatus in the same preparations has been observed 

 by me in transplantable sarcomata of rats and mice, and in the 

 uterus glands and epithelium of some mammalia by the unmodified 

 method described above, as can be seen in two of the preparations 

 I am showing. 



These various results, together with the extraordinary variations 

 in the morphological aspect of Golgi' s internal apparatus, strengthen 

 the belief that we are not faced here by mere capricious precipitations 

 of silver or by some artefact due to the methods of fixing and 

 staining. In this respect it seems to me that my preparations 

 from human Gasserian ganglion obtained five hours after death are 

 particularly interesting (fig. 2). The apparatus, fixed when under- 

 going an evident process of autolysis, has lost much of its peculiar 

 aspect and appears broken into irregularly shaped pieces, lumps and 

 granules, which also occur, for instance, in parts of transplantable 

 tumours undergoing a process of necrosis or in other degenerating 

 tissues, but not in normal freshly fixed organs. 



KeT'ERENCES. 



Golgi, C. — Une methode pour la prompte et facile demonstration de 



I'appareil reticulaire interne des cellules nerveuses. Arch. Ital. Biol., 



xlix. (1908) p. 269. 

 Perroncito, A. — Contributo alio studio della biologia cellulare. Mitocondri, 



cromidii ed apparato reticolare interno nelle cellule spermatiche. Mem. 



E. Ace. Lincei, Roma, viii. (1910) p. 6. 

 Cajal, R. S. — Formula de fijacion para le demonstracion facil del apparato 



reticular de Golgi, etc. Trab. Lab. Invest. Biol., x. (1912) p. 209. 



Alcunas variaciones fisiologicas y patologicas del apparato reticular de 



Golgi. Trab. Lab. Invest. Biol., xii. (1914) p. 127. 



Carleton, H. M. — Note on Cajal's Formalin-silver Nitrate Impregnation 

 Method for the Golgi Apparatus. Journ. R. Micr. Soc, 1919, p. 321. 



Da Fano, C. — On the so-called toning of sections stained by my modifica- 

 tions of the Bielschowsky Method and by other Reduced Silver Methods. 

 Phys. Proc. Journ. Physiol., liv. (1920). 



Method for the Demonstration of Golgi's Internal Apparatus. Phys. 



Proc. Journ. Physiol., liv. (1920). 



M 



