MODE OF ORIGIN OF NERVE FIBRES IN NERVE CENTRES. 183 



by Kolliker in their processes,* so that in this respect there does 

 not appear to be any difference between the two sets of cells. 

 The same holds good for the cells of the grey cortex of the 

 cerebrum. As Meynert and Arndt state, these possess a thicker 

 peripheric process and a large number of branched processes, 

 which are directed towards the white substance. The ganglion 

 cells have a more or less conical form, the base of the cone being 

 directed to the white substance, and sending forth a number of 

 processes which quickly ramify, whilst the apex of the cone is 

 continuous with a single, longer, thicker, and at first unbranched 

 process. In accordance with the observations of Meynert, 

 however, I have seen this process, which has been compared to 

 the axis-cylinder process, divide, sooner or later, in a dichoto- 

 mous manner, and undergo further subdivision in cells which 

 had been completely isolated by maceration in iodized serum. 

 I have witnessed a similar division in the pedunculated 

 ganglion cells of the Pes huffocampi major, respecting which 

 Deitersf was of opinion that the thicker process, constituting 

 the stalk of the cell, was an axis-cylinder process. Nevertheless, 

 I am unable to admit that either these cells or those of the 

 grey cortex of the brain can, without further investigation, be 

 classified with the multipolar cells of the spinal cord. Still it 

 is quite true that the cells of the cerebrum, as I have already 

 observed, possess an exquisite fibrillar structure, and rather 

 appear as a point of junction and intersection for nerve fibrils 

 that are already developed, than as a point of origin for those 

 which have not hitherto been in existence. 



In addition to the larger cells of the cerebrum which have 

 just been mentioned, an enormous number of smaller cells are 

 found in that organ, the nuclei of which are invested by only 

 a small quantity of cell substance. It has been demonstrated 

 that some of these give off processes, of which the ultimate 

 destination is certainly not known, but which are, nevertheless, 

 sufficient to characterise the cells as nerve cells, and to distin- 

 guish them from the connective tissue cells that are undoubtedly 

 present in the spongy connective tissue of the central organs 



* Handbuch der Geivebelehre, 5. Auflage, 1867, p. 243. 

 t Loc. cit,., p. 66. 



