150 KIYOYASU MARUI 



tical with the 'bontones de trajecto' of Cajal. Both these 'bon- 

 tones' are, generally speaking, spindle-shaped or spheroidal and 

 variously large. As far as my observations reached, there is no 

 particular difference in structure between these two kinds of 

 'bontones.' They are now and then impregnated massively or 

 as if punched; most of them show, however, the splitting up of 

 the axone fiber into several delicate neurofibrils in them, as 

 figure 8 x, indicates very distinctly. Some of them appear in 

 the .preparations in cross-section and then they show the cross- 

 sections of these delicate fibrils in them (fig. 8, xx). I must 

 emphasize here that I did not find any net structure in the 'bon- 

 tones,' as is described by many authors; the one, as we find in 

 figure 8 at xxx looks as though it had net structure, but I believe 

 it is by no means a real net-work; on the contrary, it shows 

 merely the splitting up of the axone fiber into multiple delicate 

 fibrils. Besides these large 'bontones' we find many minute 

 rings, lying close to the surface of the dendrite, and these rings 

 are continuous with very delicate fibers. The latter come from 

 the other fibers as their ramifications or from the end of the 

 large 'bontones' (fig. 8, xxxx). It is quite obvious that these 

 rings are similar to those structures which were described and 

 figured by Cajal (13). Now, the nerve fibers, which possess the 

 above-mentioned qualifications, pass sometimes very near the 

 surface of -the dendrite, and thus remind us, especially in the 

 tangential sections, of fibers coming into contact with the cell 

 surface of the dendrite by means of their 'bontones de trajecto,' 

 as was claimed by Cajal (13). But on careful observation, es- 

 peciall}^ on examination of profile pictures, we can easily con- 

 vince ourselves that there is no contact between them; at least 

 I can state definitely that there are many of these 'bontones de 

 trajecto,' which lie quite remote and free from the surface of the 

 cell (fig. 8). 



On the ventral dendrite of Mauthner's cell I found a similar 

 condition in the synapse. In the 'axone cap' we see abundant 

 unmedullated nerve fibers, which, as far as my investigation went, 

 lorm a plexus of nerve fibers. Beccari (5) used the term 'canes- 



