THE SPINAL CORD AND CEREBELLUM 153 



which is connected with the cerebellum, although it is 



easier to recognise the connection in the case of 



muscular activity owing to the suddenness and marked 



character of the changes. 



If the reinforcing influence exercised by the cere- The cere- 

 bellum as a 

 bellum be due to augmentation of chemical action, remforcing 



organ . 



how is this brought about ? There are in metabolism, 

 as has been shown, two main elements, the one 

 sensory or chemico-sensory, the other vaso-motor. 

 Let us first inquire as to the relations of the cere- 

 bellum to the vaso-motor centre in the medulla 

 oblongata. This centre, the most important, though 

 probably not the only one of its kind in the body,* 

 has been located by many observers. It is said to 

 extend from about 3 millimetres above the calamus 

 scriptorius to within 1 millimetre posterior to the 

 corpora quadrigemina,t corresponding, according to 

 Dittmar, to the anterior portion of the lateral 

 tracts, in which are scattered the ganglionic cells of 

 the upper olive (Van Deen) or the antero-lateral 

 nucleus (Clarke). According to Bechterew, a well- 

 marked bundle of fibres passes from the cerebellum 

 to the upper olive, a portion of them reaching it 



* Ferrier (loc. ait., p. 100), in dealing with this point, states 

 that the bloodvessels depend largely on the spinal centres, the 

 destruction of which, after that of the centre in the medulla, 

 causes further dilatation. As authorities he cites : Lister, ' Philo- 

 sophical Transactions, 1868'; G-oltz, 'Archiv ftir Physiologie,' 

 bd. viii., 1874; Vulpian, ' Lepons sur I'Appareil Vaso-moteur,' 

 1875. 



t Ferrier, loc. cit., p. 100. 



