394 MONTGOMERY. [Vol. XIII. 



irregular form and greater size and number, distributed in con- 

 centric circles around the centrosome (not around the nucleus), 

 the largest " Schollen " being placed peripherally.^ 



Three years previous to Dehler's researches, Vas ('32) studied 

 the chromophilic bodies, which he termed " chromatin," in 

 sympathetic ganglion cells of man, horse, dog, and rabbit; they 

 are, in these forms, smaller than those observed by Dehler in 

 the frog. Vas did not notice a concentric arrangement, but 

 found the largest bodies peripherally situated. He makes the 

 interesting observation that the granules are absent in the cells 

 of the human foetus, and first appear after birth. 



The chromophilic granules of ganglion cells, such as have 

 been described (mainly for vertebrates) by Flesch ('86a, b), H. 

 Virchow ('88), Nissl ('94a, b, and previous papers), de Quervain 

 ('93), van Gieson, Lenhossek ('95a), Pfiiicke ('95), and others 

 have but little resemblance to the chromophilic corpuscles of 

 Lineus. For the " granules " are much smaller, usually spindle- 

 shaped, and are arranged concentrically around the nucleus. 

 One point of similarity may be referred to, however: the 

 chromophilic granules as well as the corpuscles occur only in 

 the cytoplasm of the cell, never in the nucleus nor in the axis 

 cylinder. Lenhossek ('95a), who has studied the chromophilic 

 granules in the multipolar spinal ganglion cells of Homo, Bos, 

 and Lepus, states : " Es ware allerdings moglich, dass sie, wie 

 de Quervain ('93) vermutet, durchgehends Komplexe von feine- 

 ren Kornchen sind, aber ein solcher diskontinuierlicher Aufbau 

 lasst sich nur an einer kleinen Anzahl von Schollen nachweisen" ; 

 and notes that although the chromophilic granules do not enter 

 the axis cylinder, they nevertheless penetrate the dendritic 

 processes for a short distance. 



The recent paper by Pfliicke ('95), based upon studies on 

 ganglion cells of Lumbriats and Mollusca (fixed with sublimate), 

 describes as follows the arrangement of the chromophilic gran- 

 ules : " Der Zellleib der Nervenzelle besteht aus varikosen 



1 Centrosomes were discovered for the first time in ganglion cells in the frog 

 by Lenhossek ('95b) and Dehler ('95), independently of one another; by the 

 former in the spinal ganglion cells, by the latter in those of the sympathetic 

 ganglia. I have not found centrosomes in the ganglion cells of the nemerteans. 



