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HANDBOOK OF PHYSIOLOG1. 



found in the internal capsule, viz. , those from the frontal lobes are 

 situated at the extreme tip of the front limb, in front of the motor fibres 

 from the same district, and others from the temporal-occipital district 

 converge to the posterior part of the hind limb. Those passing between 

 the occipital lobe and the optic thalamus are believed to be concerned 

 with vision, and are called fibres of the optic radiation. 



It may be as well to mention here that some other fibres from the 

 temporo-occipital lobe pass into the optic thalamus, without forming a 

 part of the internal capsule. 



The optic thalamus then receives fibres from nearly all parts of the 

 cerebral cortex, some of w r hich are not found in the internal capsule. 

 The tegmentum, the afferent or sensory tract of the crus to a great ex- 

 tent ends in the optic thalamus, and is, therefore, connected through it 

 with nearly all parts of the cortex, indirectly. It is also more directly 

 connected with cortex (a) by fibres of the optic radiation which do not 

 go to the optic thalamus, (b) by fibres from the frontal and parietal 

 lobes, which pass through the lenticular nucleus, and (c) by fibres from 

 both the lenticular and caudate nuclei of the corpus striatum. 



In the tegmentum the longitudinal fibres may be thus enumerated : 



(a.) Thefilktj which consists of fibres from the sensory decussation of 



Fig. 385. Vertical section through the cerebrum and basic ganglia to show the relations of 

 the latter, co, cerebral convolutions ; c,c, corpus callosum; v. I., lateral ventricle; f, fornix; 

 vlIL, third ventricle; n.c. , caudate nucleus; th, optic thalamus; n.l., lenticular nucleus; c.i. , 

 internal capsule; c. Z., claustrum; c.e., external capsule; m, corpus mammillare ; t.o., optic 

 tract; s.t.t., stria terminalis ; ?i.a., nucleus amygdalae ; cm, soft commissure. (Schwalbe.) 



the bulb, which becomes longitudinal in the inter-olivary region, and in 

 its course upward, from masses of gray matter, such as the superior 

 olive; it divides into two bundles, (i.) Lateral, ends in gray matter 

 of posterior corpus quadrigeminum and in white matter beneath the 

 anterior, and (ii.) median, ends in anterior corpus quadrigeminum and 



