Ken YON, The Brain of tJie Bee. 143 



would be recognizable only in sections. Even in these its boun- 

 daries are indefinable. 



THE CEREBRAL NERVES. 



From the lower side of the antennal lobe there is given off 

 the large antennal nerve, which passes forward and slightly 

 downward to the entrance of the antennae. From the lower 

 surface behind the origin of the large nerve there originates 

 a small one that may be readily traced in sections to the anten- 

 nal muscles within the head. This, which I will denominate 

 the antcmio-motor intcmus, in contradistinction to the other, or an- 

 temio-motor extcrmis, was first discovered and traced to its termi- 

 nation in the muscles by Newton ( 79) in his study of the brain 

 of the cockroach. It is described by Viallanes (g?) in his 

 paper on the brain of the wasp as the " nerf antennaire acces- 

 soire " and was correctly identified by him with the nerve de- 

 scribed by Newton, although he was unable to trace it to its 

 termination in the muscles. Doubtless it may be found as a 

 separate nerve in all tracheate arthropods. One occupying the 

 same position I have recognized in Scalopendrella immaciilata 

 and traced into muscles that I supposed to belong to the an- 

 tennae. 



Behind this internal antenno-motor nerve and immediately 

 behind the base of the antennal lobe there is a somewhat larger 

 nerve that I have traced towards the mouth-parts of the bee 

 and from its position take to be the labral nerve. This arises 

 from the trito-cerebron and may be seen in fragment in the pho- 

 tograph (fig. 2, PI. XIV), which is of a section slightly too far 

 forward to show the lobe and the entering nerve root. 



From the lower side of the ventro-cerebron (PI. XX) there 

 arise not far apart from each other three pairs of large nerves 

 that like the one just described may be readily traced to the 

 mouth parts. Since in most of my preparations these parts 

 were cut away to allow a free access of the fixing fluids to the 

 brain or to free the object as much as possible from chitinous 

 parts to avoid tearing during the process of sectioning, I have 

 not yet traced the nerves to their endings. From their posi- 



