rrtrh.hca 



p.o.Ih. 



trtlh.h c.a. 

 frthla. 



trtlh.h.c.p. 

 Top. 



com.post 



trrtpedpost 



cYmes. 



com.ch 



Fig. 54 From the same series three sections farther medialward. The 

 caudal part of the hji-pothalamus is defective. From the heavily impregnated 

 marginal optic tract (tr.op.) dense fascicles of collaterals pass off into the pars 

 optica thalami {p.o.th.). The fibers of the unmyelinated component of the trac- 

 tus tecto-thalamicus et hjrpotlialamicus cruciatus anterior {tr.t.th.h.c.a.) are 

 finer and less deeply impregnated. They do not appear to participate in the 

 neuropil of the pars optica thalami. The fibers of the so-called basal optic 

 bundle (tr.op.b.) appear to end in the area lateralis tegmenti (a.l.t.) in front of 

 the III nerve. These fibers are mingled with others of uncertain origin, prob- 

 ably from the hypothalamus (t7-.mam.ped.), and probably also with fibers of 

 the ascending visceral tract (ir.v.a.) and tractus tecto-peduncularis posterior 

 (tr.f.ped.post.) farther medially. The tractus tecto-thalamicus et h5'pothal- 

 amicus cruciatus posterior (tr.t.th.h.c.p.) is for the most part unimpregnated; 

 cf. fig. 56. X 30 rU, 30). 



340 



