strmed 



trth.p.ds. 



MIDBRAIN AND THALAMUS OF NECTURUS 



' "^^ par ,_^ :, 



strmed 



327 



•Tr:tth.h.ap. 



trTthh.cp. 

 com. post 

 Tr sp.th. 



com.cb. 



com.cb. 



diencephali. This neuropil is reached by dendrites of neurons whose cell bodies 

 lie adjacent to the subcommissural organ, some of which are imperfectly impreg- 

 nated in this preparation. In several cases axons are seen arising from the bases 

 of these dendrites and directed laterally without decussation among the fibers 

 of the commissura posterior. These neurons may be related at their bases with 

 the subcommissural organ, thus providing a correlation mechanism between 

 stimuli arising at the attachment of Reissner's fiber (fig. 62, f.R.; cf. Nicholls, 

 '12 and '17) and the fibers of the peripheral neuropil. But further details are 

 necessary before this suggestion can be adopted. On the right side in the area 

 marked col.inf. is a dense neuropil (not drawn in) reached by terminals of the 

 acoustico-lateral lemniscus (Im.). A few free terminals of this lemniscus are 

 shoTVTi on the left side; cf. figure 56. X 23 (cviic, 10). 



THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 28, NO. 2 



