268 



INNERVATION. 



[CHAP. x. 



numerous transverse fibres pass into the central and posterior part 

 of the medulla. It is not unlikely that many of these so called 

 fibres may be bundles of nerve tubes, but it is also highly probable 

 that many of them are bloodvessels, which pass in great numbers 

 into the central substance of the medulla. The same mode of 

 connexion which exists between the roots of the nerves and the 



Fig. 70. 



Transverse section of the medulla oblongata through the lower third of the olivary bodies. (From 

 Stilling.) Magnified 4 diameters. 



a. Anterior fissure, b. Fissure of the calamus scriptorius. c. Raphe*. d. Anterior columns. 

 e. Lateral columns. /. Posterior columns, g. Nucleus of the hypoglossal nerve, containing large 

 vesicles, h. Nucleus of the vagus nerve. , i. Gelatinous substance. k t k. Roots of the vagus 

 nerve. I. Roots of the hypoglossal, or ninth nerve, m. A thick bundle of white longitudinal fibres 

 connected with the root of the vagus, n. Soft column (Zartstrang, Stilling), o. Wedge-like column 

 (Keelstrang, Stilling), p. Transverse and arciform fibres, q. Nucleus of the olivary bodies, r. The 

 large nucleus of the pyramid, s, s, s. The small nuclei of the pyramid, u. A mass of gray sub- 

 stance near the nucleus of the olives (Oliven-Nebenkerri) . u, q, r, are traversed by numerous fibres 

 passing in a transverse semicircular direction, v, w. Arciform fibres, x. Gray fibres. 



spinal cord, whatever that may be, will no doubt be found to pre- 

 vail in the medulla ; and as several important nerves emerge from 

 this portion of the encephalon, it seems very likely that their 

 fibres should penetrate to its central part to form a connexion with 

 its gray matter. This question, however, is not to be decided 

 by the use of low powers of the microscope, such as Stilling 

 employs; nor have our trials with higher ones as yet led to any 



