42 Journal of Comparative Neurology. 



cells is most beautful, but when osmic solutions are used the 

 contents of the vesicles is blackened and the result is a granular 

 appearance instead. The pericellular mesh-work is stained red 

 by picrocarmine, as is all protoplasmic matter, while the nuclei 

 are all selected by the haematoxylin. Nerve fibers stain red but 

 their nuclei are purple. The nerve supply is abundant and the 

 fibers can be traced without difficulty through the corium layer 

 in all preparations. The sheaths seem to cease after passing the 

 corium and the subsequent course is less easy to make out. In 

 a considerale number of cases it has been possible to trace such 

 fibers with all desirable clearness to actual connection with the 

 bases of the lower protoblasts above mentioned. The fiber is 

 red, as is the protoplasm, so that it remains possible that the 

 exact nature of the union is not obvious, yet from the fact that 

 two masses of naked protoplasm thus come in contact, the range 

 for possible modes of union cannot be extensive. In any case the 

 most careful examination under immersion lenses of well-stained 

 specimens does not reveal any form of intermedation between 

 the fiber and the protoplasm of the cell. Nor is this relation 

 limited to the lowest layer of protoblasts alone, for it is possi- 

 ble to trace fibers to some of the higher members as well. The 

 attempt has repeatedly been been made to count the number of 

 fibers entering the given area and then to compare this number 

 with the number of protoblasts in the same area, with the re- 

 sult that the fibers proved more numerous than the cells in the 

 lower series, thus offering independent evidence to the effect 

 that these fibers are destined to more than the single basal row 

 of protoblasts. 



The pericellular net-work has been described by a number 

 of the earlier observers, but in each case the real nature of the 

 structure has not been detected. Paulicki and Pfitzner both re- 

 garded it as a mesh-like thickening of the cell wall. The latter 

 thinks these "ribs" serve for the point of attachment of the 

 "intercellular bridges." Part of Paulicki's description is given 

 in full. "An einigen Leydig'schen Zellen wurde ich auf kleine 

 kreisformige, lanzende, dunkelconturirte Figuren aufmerksam, 

 die in ziemlich regelmassigen Abstanden von einander entfernt 



