232 PHYSIOLOGY OF CENTRAL NERVOUS SYSTEM. 



yet entirely known. Without attempting to recall all of these 

 connections, which will be found described in works upon anat- 

 omy or neurology, emphasis may be laid upon those which are 

 at present helpful in discussing the physiology of the organ. 



1. Connections with the Afferent Paths of the Cord. — Through the 

 inferior peduncles (restiform bodies) the cerebellum receives affer- 

 ent fibers from the spinal cord and the medulla. The cerebello- 

 spinal fasciculus (tract of Flechsig) undoubtedly terminates in the 

 cerebellum, entering the organ through the inferior peduncle or 

 restiform body. Another afferent tract of the cord, that of Gowers 

 (fasciculus anterolateraUs superficiaUs), ends in the cerebellum, in 

 large part at least, forming a part, in fact, of the cerebellospinal 

 system. The nature of the sensory impulses conveyed in this way 

 to the cerebellum is not entirely understood, but it seems certain 



Fig. 103a. — Diagram indicating some of the afferent and efferent connections of the cere- 

 bellum. The afferent or incoming paths are indicated in blue; the efferent or outgoing paths 

 in red: 1, the fibers from the tract of Flechsig; 2, the fibers from the tract of Gower; 3, fibers 

 from Deiter's nucleus; 4, fibers of the cortico-ponto-cerebellar tract; 5, fibers arising from the 

 Purkinje cells and ending in the dentate nucleus; 6, fibers from the dentate nucleus ending in 

 the red nucleus; 7, fibers of the rubrospinal tract. 



that in good part the peripheral nerve fibers concerned arise in the 

 muscles and their ligaments, and in the ligaments around the joints. 

 This tract and the similar tract of Flechsig, by forming an afferent 

 connection between the deep tissues and the cerebellum, present a 

 mechanism which may be used to explain the influence exercised 

 by the cerebellum upon muscular activity. 



2. Connections with the Vestibular Branch of the Eighth Cra- 

 nial Nerve. — This branch, arising in the semicircular canals and 

 utriculus and sacculus, ends in the pons in the so-called vestibular 

 nuclei in the floor of the fourth ventricle, the nucleus of Deiters, 

 the nucleus of Bechterew, and the nucleus triangularis. From these 

 nuclei some fibers pass to the nucleus tecti of the cerebellum and 

 thus establish a connection between this organ and the semicir- 

 cular canals. 



