127 



gsr ones. Tii?roiis extsnl into the leniritas for a short ii.s- 

 tance, only. 



The axons takes its ori^,in directly from the cell-body, 

 so far as observed (*ig.3n). It gives off collaterals during 

 the first part of its length. The several axones descend to 

 the base of the forebrain and ran posteriorly in the tractus 

 strio-thalaiiicas for ultirnate termination in the thalamus; see 

 Section VII. This conspicuous fibre-tract was described by 

 Rohon ('77) as the peiunoul'is cerebri; by Sanders ('3^) as the 

 arus cerebri; and by idinger in his earlier ^ork ('88) as the 

 basale vorierhi rnbundel . 



The general striatum has the type of structure and the 

 associations «hich are characteristic of motor centres. The 

 large neurones, with their long and videly spreading denJrites, 

 enter into a nexus with the axones derived from a purely senso- 

 ry centre, the epistriatum. Tne latter receives, chiefly, 

 impressio-is of the olfactory order. The neurones of the stri- 

 atum are indirectly affected through the axones of the epistri- 

 atum, carrying, in tarn, the nervous disturbance to the inter- 

 brain, whence a relay carries it to the great roof-nucleus of 

 the midbrain for direct connection with the neurones of the 

 body musculature. The enormous olfactory organs of Mustelus 

 indicate how important the olfactory sense must be in the econ- 

 omy of tne animal, and observation demonstrates the large place 

 taken by olfactory impressions in the location of food. The 

 striatui^i is evidently the centre for motor reflexes, of which 



