192 Journal of Comparative Neurology. 



region. The others come into close contact with the hinder 

 surface of tlie brain and pass on downward in the upper sur- 

 face of the oesophageal commissures to the ventro-cerebron, 

 whence they pass on backward along the dorsal surface of the 

 ventral cord, thus effectually disproving Binet's (91) assertion 

 that there are no large fibers in the dorsal region of the cord 

 comparable to those found in Crustacea. In many cases I have 

 found these large fibers of the cord in bichromate of silver 

 preparations passing along the dorsal surface of the ventro- 

 cerebron on into the region just below the level of the central 

 body as shown in PI. XX. What their significance may be I 

 do not at present undertake to say. Had Binet persevered 

 longer in his trial of either of the two methods preeminent in 

 the study of the nervous system, he probably would have found 

 them. But while the existence of the large fibers is beyond 

 question, there is still a chance that my description of them as 

 coming from the ocelli is erroneous, for the reason that I have 

 not been able, in specimens prepared by the bichromate of silver 

 method or by any other, to follow a fiber through an unbroken or 

 unsectioned course from the ocellar ganglion or the upper por- 

 tion of an ocellar nerve to the ventral cord. Yet impregnated 

 fibers have been followed without interruption from the copper- 

 the level indicated above, and a the large fibers have been care- 

 fully traced through sections treated according to my copper- 

 haematoxylin method. It should be noted that Cuccati (ss) 

 also traced them in Samomya, as I have done here, into the 

 ventral cord. Viallanes (S7,88) did not succeed in following 

 them below the fibrillar mass behind the inner root of the 

 mushroom bodies. 



THE fibers from THE BRAIN TO THE OCELLAR GANGLIA. 



Besides the fibers just described as constituting tlie ocellar 

 nerves there may, in preparations by the bichromate of silver 

 method, be distinguished others of an efferent nature (fig. 42, 

 PI. XXII). These may be traced from below the level of the 

 calices into the ocellar ganglia where they branch arborescently. 

 None are large. Where they originate or what may be their 



