136 KIYOYASU MARUI 



Ramon y Cajal (12) emphasized on the basis of his study by his 

 own technic a reticular structure of the neurofibrils in the gan- 

 glion cells. He distinguished two kinds of fibrils — the primary 

 and the secondary neurofibrils ; described the existence of a super- 

 ficial and a deep neurofibril net-work, and he stated that the 

 parallel fibrils of the dendrites enter into correspondence with 

 both the net-works. He declared, moreover, that the fibrils of 

 the axis-cylinder originate from both these reticula. Retzius (26), 

 V. Lenhossek, and Held (19, 20) produced by means of Cajal's 

 method similar results as Cajal, while others (Marinscu, v. Ge- 

 huchten, and others cited in 15) maintained a certain reserve 

 on this point, at least for some cell types. Bielschowsky (8), 

 who studied the motor cells of the anterior horn by Cajal's 

 method, pointed out the disadvantages of the latter, through 

 which a false picture of a reticulum might be brought out. Wolff 

 (28) expressed an opinion concerning the spatial relation be- 

 tween the honeycomb of the protoplasm and the neurofibrils 

 and declared that the neurofibrils always lie in the wall of. the 

 former. According to Economo, the neurofibrils through simul- 

 taneous impregnation of this 'wall of the honeycomb pattern 

 may look as if they were connected by cross-beams so as to form 

 a net-work. 



As far as the anastomotic connections between the neurofibrils 

 are concerned, Wolff (28) did not want to speak of a real net- 

 work; on the contrary, he assumed theoretically a plexus forma- 

 tion of the neurofibrils. Heidenhain also, on the basis of the 

 theoretical considerations, assumed a metaplexus in the cell. In 

 the present work, however, I will not enter further into theoreti- 

 cal considerations, but restrict myself merely to the microscop- 

 ically visible things. I came to the conclusion that the neuro- 

 fibrils in Mauthner's cell form no net-work at all. Above all I 

 wish to emphasize here that I could not observe any neurofibril 

 reticulum in this cell even in my best preparations with Cajal's 

 and Levaditi's methods (fig. 2). 



