CHAP. XXIV.] PRINCIPAL PARTS OF THE BRAIN. 503 



organ of Conscious Intelligence, viz., the Cerebrum. It 

 is the ' Actuation,' or carrying into effect of a Volition 

 destined to issue in Movement, which devolves upon 

 Motor Centres, and there is reason to believe that the 

 Cerebellum co-operates with the Corpora Striata in the 

 realization of this secondary part or phasis of an ordinary 

 Volitional Act and its consequence. 



Two principal questions present themselves, therefore, 

 as a result of what has been hitherto said concerning the 

 probable functions of the Cerebellum. (1) What evidence is 

 there to show that the Cerebellum is largely concerned in 

 the production of ' automatic ' and ' secondary-automatic ' 

 Movements in response to 'unfelt' Impressions ? (2) What 

 evidence is there to show that the Cerebellum is con- 

 cerned in the execution of Voluntary Movements ? 



The answers to these questions, so far as they can be 

 given and that by way of suggestion rather than as 

 positive affirmations may be best set forth in connec- 

 tion with some statements as to what is known of the 

 composition of the several Peduncles of the Cerebellum. 



There is reason to believe that it is principally through 

 the intervention of the Upper and Lower Peduncles that 

 the Cerebellum receives impressions of an unconscious 

 order, which enable it to take part in the production 

 of certain responsive ' automatic ' and * secondary-auto- 

 matic ' Movements. 



The reasons in favour of this view are, first, that the Upper and 

 Lower Peduncles contain many different kinds of ' ingoing ' fibres, 

 although it has been abundantly proved that the Cerebellum is in 

 no sense an organ of Conscious Intelligence; secondly, it is sup- 

 ported by the fact that in Fishes and Eeptiles these Peduncles 

 alone exist the Middle Peduncles, and with them the 'pons 

 Varolii,' being notoriously absent. For it is reasonable to suppose 

 that the mere 'automatic 1 or ' sensori-motor ' functions of the 



