650 Dynamic Theory. 



lum and the basal ganglia, constitute three other such complete ma- 

 chines. The same is equally true of the cerebrum. Its motive power, 

 like that of a muscle, is furnished by the consumption of its own tis- 

 sues, the loss of which is made good by the blood ; but the stimulations 

 which come to it from the environment furnish the disturbance which is 



_, J54. Scheme of the Brain. 



C <7.-Cortex of Cerebrum. 



Cs Corpora Striata. 



to. Optic Thalamus. 



ril Lenticular Nucleus. 



v Corpora Quadrigemina. 



Fed. Peduncles, or Crura Cerebri. 



. Crusta. 



n. Tegmentum. 



If. Section of Peduncles (or cord). 



vw. Anterior roots. 



hw. Posterior 



FIG. 354. 



2. -Corona radiata of Lenticular Nucleus. 



3. Optic Thalamus. 



4. Corpora Quadrigemina. 



5. Direct fibres from the Cortex. [Tegmentum. 



6. Fibres from the Corpora Quadrigemina to the 



m. Continuation of these. 



8. Fibres from Corpus Striatum and Lenticular 



Nucleus to the Crusta of Peduncle. 

 M. Continuation of these. 

 ss. Course of sensory fibres. 

 7 Sensory fibres to optic thalamus. 



1 1. Corona radiata of Corpora Striata- 

 necessary to set this motive power in action, precisely as the same sort 

 of stimulations set off the reflex action of the spinal cord. Meynert's 

 diagram, fig. 354, shows very well the relationships of the different 

 parts of the brain to each other, and the course of the stimulations. 

 Direct afferent fibres pass from the posterior part of the peduncles of 



