238 JOHNSTON. [VOL. I. 



This bundle is formed in the ventral part of the olfactory lobe, 

 enters the fore-brain through the nucleus postolfactorius ven- 

 tralis, courses round the lateral surface of the nucleus postol- 

 factorius lateralis, and enters the epistriatum at its dorso-lateral 

 angle (Fig. 2). I have traced olfactory tract fibers into the 

 epistriatum and into the two nuclei postolfactorii. I have 

 been unable to trace any fibers between the anterior commis- 

 sure and the olfactory lobe. Although we might expect to 

 find olfactory tract fibers ending in the nucleus thaeniae and 

 in the area described as cortex, I have been unable to trace 

 them to either with certainty. 



(2) The tractus strio-thalamicus, considered as including all 

 fibers connecting the fore-brain with the ventral portion of the 

 'tween-brain, is divided into three portions : the median, lateral, 

 and ventral bundles. The median bundle is much the largest, 

 and occupies the position indicated in Figs. 2, 3 (Tr. strio-tJial. 

 med.), and 4 (D}. It contains the descending axis cylinders of 

 the cells of the striatum and the ascending fibers from the 

 thalamus to the epistriatum. The lateral bundle (Figs. 2 and 

 3, Tr. strio-tJial. /at., and Fig. 4, C) contains fibers arising 

 from the nucleus postolfactorius lateralis and from the ante- 

 rior part of the striatum. Its course has been described. The 

 ventral bundle (Figs. 2 and 3, Tr. strio-thal. ven., and Fig. 4, 

 B] consists only of fibers from the nucleus postolfactorius 

 ventralis whose course has been described above. 



(3) The tractus olfacto-habenularis (Fig. 4, E} arises from 

 cells of the nuclei postolfactorii and probably from cells of 

 the cortical area and of the nucleus thaeniae, and passes to the 

 ganglion habenulae where most or all the fibers cross to the. 

 opposite side to end among the dendrites of the cells giving 

 origin to the bundles of Meynert. That the bundles here 

 described are equivalent to more than Edinger's tractus olfacto- 

 habenularis is shown by their relation to the anterior commis- 

 sure. The tract to which Edinger gives this name arises in 

 the ventrally situated nucleus thaeniae and area olfactoria and 

 runs behind and below the anterior commissure (see Edinger, 

 '96a, p. 343, Fig. 5, or '96b, p. 148, Fig. 100), while the larger 

 part of the fibers here included under that name arise in the 



