618 



THE FUNCTION OF THE SPINAL CORD 



pass into the gray matter of the upper spinal cord. The cerebellar groups remain 

 largely uncrossed. 



(c) The superficial anterolateral tract (Gower's). — The origin of these fibers in 

 the lower spinal gray matter and their distribution to the cerebellum and related 

 parts suggest that they convey afferent impulses from the posterior roots to the 

 cerebellum/ and hence, their function must be similar to that of the fibers of 

 Flechsig's tract. They are concerned with the coordination of muscular move- 

 ments, their immediate purpose being to aid in the conduction of the impulses from 

 the receptors in the muscles, tendons and joints to the coordinating organ, the cere- 



FiQ. 307. — Diagram or the Spinocerebellar, Bulbotegmental, Cerebellotegmental, 



PONTOTEGMENTAL, AND PONTOCEREBELLAR TRACTS. 



OT, Optic thalamus; F, fillet; RN, red nucleus. {After v. Gehuchten.) 



bellum. For this reason, they may be regarded as forming a part of the afferent 

 arc required for the production of the muscle sense and coordination of muscular 

 action. That this is true may also be gathered from the fact that the division of 

 this tract is followed by a moderate degree of atonia and ataxia^ below the seat of 

 the lesion. 



{d) The spinothalamic and spinotectal tracts are really a part of Gower's tract. 

 These fibers traverse the medulla and pons and terminate very largely in the optic 



* Bruce, Quart. Jour, of Exp. Physiol., iii, 1910, 391; also see: Lewandowsky, 

 Untersuchungen iiber die Leitungsbahnen d. Truncus cerebri, etc., Jena, 1904. 



2 Bing, Archiv fiir Physiol., 1906, 250; also see: Horsley and Macnalty, Brain, 

 1909, 237. 



