196 Journal of Comparative Neurology. 



ventro-cerebral and commissural region. Lower down in the 

 ventro-cerebron another fiber is shown (fiber 41) that branches 

 among the fibers from the oral nerves and thence apparently 

 ■passes backward into the ventral cord. A smaller fiber (40) 

 makes the same connections. 



In some of my preparations there may be distinguished 

 what may be described as a roll of fine fibers, the individual 

 fibers of which cannot be traced, that passes through the ven- 

 tro-cerebron and thence upward through each commissure ; 

 whence it crosses to the opposite lower side of the dorso-cere- 

 bron or over the anterior part of the roof of the oesophageal 

 foramen. I do not know what this can be unless it is a contin- 

 uation of the ventral column described by Binet (94). Its pas- 

 sage into the dorso-cerebron is directly contradictory of this au- 

 thor's assertion that " il n'existe dans le ganglion sous cesopha- 

 gien aucun croisement des connectifs qui prennent leur origine 

 dans le cerveau." But Viallanes (87,88) speaks of a fibrillar 

 tract that passes from the cord to the opposite side of the dorso- 

 cerebron. In close connection with this roll individual fibers 

 may be followed from the cord to the same destination. 



What is apparently a branch of this roll continues upward 

 towards the central body in the commissure of the same side, 

 or without crossing the median line. 



It is this roll of fibers that has already been mentioned in 

 connection with the dorso-ventral tract, wath the fibers of which 

 it seems to come into contact. Assuming that, which is doubt- 

 less true, it is the continuation of the ventral columns described 

 by Binet (94) and that the root of the crural and the alary 

 nerves terminating in it are sensory, which is also probably 

 true, there is then seen to be a direct sensory tract for external 

 stimuli from all parts of the body to the calices of the mush- 

 room bodies, a fact of no little importance in completing the 

 chain of evidence demonstrating that the cells of these bodies 

 are the ones that enable the animal to adapt itself to the vary- 

 ing conditions of life. 



A similar group of fibers may be followed in copper-haema- 

 toxylin preparations from the ventral cord through the ventre- 



