490 E. V. Cowdry, 



are not cliromiclia but that they belong to the conception of the 

 chromidial apparatus. 



Marcora (1909) demonstrated the morphological independence of 

 the Nissl substance and the internal net in the same cell b}^ means 

 of the latest Golgi method, followed by staining with magenta red. 

 Double staining was also accomplished by Collin and Lucien in the 

 same year (Jahresber. der Anat., 1909, p. 412). In reply, Legendre 

 (1910, p. 216), on the basis of many questionable analogies, states 

 that the internal reticular appai^atus of Golgi and the chromatophile 

 substance (Nissl bodies) are probably identical. A few months prior 

 to this Hoven (1910, p. 479) came to the conclusion that certain per- 

 sistent chondriocontes correspond to the internal reticular apparatus 

 of Golgi, the Binnennetz of Kopsch, etc. Popoff (1906, p. 258), Meves 

 (1908, p. 846, and 1910a, p. 655), and Van Durme (1907, quoted by 

 Meves), also suggest that the Binnennetz is formed of mitochondria. 

 Furthermore, Smirnow (1907) intimates, on the basis of his investiga- 

 tions on plant cells, that the mitochondria or the chondriomites 

 are the same thing as the reticular apparatus of Golgi.. Others 

 have come to the conclusion that the reticular apparatus is an 

 artefact. 



Attempts to study the canalicular system in living, unstained, 

 spinal ganglion cells proved futile; for it could not even be seen. 

 This canalicular system is, nevertheless, not an artefact produced by 

 the action of fixing agents because I have frequently been able to 

 demonstrate it by staining intra vitam with pyronin. To bring about 

 this result spinal ganglia are injected with, or teased out, and immer- 

 sed in, a 1 : 1,000 solution of pyronin in 0,75 "/o sodium chloride 

 solution. The individual cells must be isolated more or less complete- 

 ly by means of finely pointed needles. Cells may sometimes be seen 

 in which the canals stand out as clear spaces in a very finely gran- 

 ular red-stained cytoplasm (fig. 15). The nuclear sap often absorbs 

 some of the dye and the nucleolus is coloui^ed. Such preparations 

 remain unaltered for about an hour, so that ample time is afforded 

 for a thorough examination of them. 



Canals such as these occur in spinal ganglion cells fixed in a 



