1/52 GANGLION-GLOBULES. 



Remak as existing upon these fibres. The similarity between 

 the organic fibres and that which I have described as the 

 earlier condition of the white nervous fibres, might be adduced 

 as an objection to my description of the formation of nerves, 

 and it might be said, that that form seemed to be the earlier 

 form of the white nervous fibre, because the organic nerves 

 were developed earlier than the white, and, therefore, organic 

 fibres were the only ones present in the first instance. Ob- 

 servation of the actual transition, as represented in pi. IV, 

 fig. 8, c d, would, however, refute this argument. Each pale, 

 nucleated fibre becomes a white nervous fibre, as an immediate 

 consequence of the formation of the white substance, which 

 is probably a secondary deposit upon the internal surface 

 of the hollow fibre. The formation of this white substance, 

 which, according to analogy, must occur in every one of the 

 minutest fibres, either does not take place at all in the organic 

 fibres, or does so at a much later period, and their peculiarity 

 therefore consists in their remaining stationary at an earlier 

 stage of development, and either never attaining to the higher 

 development of ordinary nerves, or only at a much later period, 

 (a point which might be decided by comparing their numbers 

 in old and young individuals.) One can conceive that the 

 function of the organic nerves, whether it be actually a che- 

 mico- vital one, or consist merely in the production of in- 

 voluntary motion, requires less-developed nerves, in the same 

 way that the involuntary muscles do not attain the same de- 

 gree of development as the voluntary. 



2. Ganglion-globules. 



These occur in the gray substance of the brain and spinal 

 cord and in the ganglia, having generally the appearance of 

 comparatively large granulous globules, enclosing a round vesi- 

 cle, placed eccentrically, and which again exhibits in its 

 interior one or two small dark points. According to Eemak, 

 two of these vesicles sometimes occur in one globule. Valentin 

 (Nov. act. Acad. Leopold, xviii, p. 196), calls attention to 

 the similarity between their composition and that of the egg, 

 he compares the vesicle of the ganglion-globules to the germi- 

 nal vesicle, their parenchyma to the yelk-substance, and ascribes 



