fmecl.t 



trih.fa 



5Ti:med. 



ttrtthhca 



trth.h.p.c 

 Trt.th.h.c.p. 

 tr:th.h.p.c.x 

 Trmam.ped. 



trtped.post 



Fig. 55 From the same series two sections farther medialward. Two of 

 the components of the lateral forebrain bundle (f.lat.t.) are clearly shown. 

 Axons of the tractus thala.mo-fr on talis anterior (IrJ.h.f.a.) leave the pars dorsalis 

 thalami (p.d.th.) in slender wisps of closely crowded fibers to turn forward in 

 the lateral forebrain bundle. Other fibers of this bundle (tr.fit.t.) enter the 

 ventral tegmental fascicles if.v.t.). The more slender and scattered fibers of 

 the tractus thalamo-hypothalamicus et peduncularis cruciatus (tr.th.h.p.c.) 

 are seen to arise from the pars dorsalis thalami mingled with those of the tractus 

 thalamo-frontalis. Some of the fibers of the former tract, after their decussa- 

 tion, are shown (tr.th.h.p.c.x.) to enter the ventral tegmental fascicles. The 

 tractus tecto-thalamicus rectus (Ir.t.th.r.) is seen entering the pars dorsalis thai- 

 ami. No attempt has been made to represent the dense neuropil in this region, 

 composed of the three types of axons figured and dendrites from the underlying 

 stratum griseum. The fibers of the medial forebrain bundle (f.med.t.) are very 

 incompletely impregnated. Some enter the hypothalamus and some the ven- 

 tral part of the motor tegmentum of the cerebral peduncle. X 30 (U, 32). 



341 



