CuRRAN, A New Association Fiber Tract. 653 



down on the external side of the lenticular nucleus — the compact 

 bundle is seen distinctly in all the dissections, Plates I and 

 II. Since this is the place in which it is most marked as a separate 

 tract, I shall begin a somewhat detailed description of it here. The 

 dissections are self-explanatory, and it is only necessary to mention the 

 sti-uctures in direct relation with the fasciculus. If we turn to 

 Figs. 1 and 2 we can see that the whole of the middle and posterior 

 parts of the fasciculus uncinatus lie below the fasciculus occipito- 

 f rontalis inferior. The upper part of the fasciculus uncinatus has been 

 removed so that we may be able to see the lower part of the fasciculus 

 occipito-frontalis inferior. In Fig. 3, the fasciculus uncinatus has been 

 wholly removed to show more thoroughly the other structures which 

 form the bed on which the fasciculus occipito-frontalis inferior lies at 

 this position. The picture is not an exact lateral view. The cerebellar 

 end is raised so that the photograph would show part of the under 

 surface of the lenticular nucleus and the relation of the anterior com- 

 missure. It will be noticed that the anterior commissure turns up 

 and enters the temporal lobe (Ant. C^ and C^) where its fibers spread 

 out and mingle wdth the temporal part of the corona radiata. This 

 is shown in Figs. 3 and 4 and is present but not clearly seen in Fig. 2. 

 These two systems, the corona and anterior commissure, together with 

 part of the fasciculus uncinatus, which is removed in Fig. 3, but 

 shown in Fig. 2, form the bed on which this part of the fasciculus 

 occipito-frontalis inferior rests. This bed is supported by the roof 

 of the descending horn of the lateral ventricle (Roof desc. h. Fig. 

 3) which consists, on its upper surface, of the fibers from the 

 temporal part of the corona radiata ; then from above down those 

 from the tapetum, from the stria semicircularis, and from the tail 

 of the nucleus caudatus. ISTear the end of the temporal lobe the 

 amygdaloid nucleus with its great radiation to the cortex — the fasc. 

 amygdalo-temporalis (F. a. t., Fig. 2) lie under the temporal part 

 of the corona radiata. 



The posterior part of the bed of the fasciculus occipito-frontalis 

 inferior, behind the posterior end of the lenticular nucleus, is made 

 up of the following structures from above downward : — optic radia- 

 tion, tapetum, and the ependyma of the post, horn of the lat. 

 ventricle. This holds good all the way back, from the posterior end 



