TRANSVERSE FIBERS OF PONS. 271 



TRANSVERSE FIBERS OF PONS. 



The transverse fibers form three consecutive layers in the pons, 

 viz., the anterior, the middle, and the posterior layer. They 

 lie one upon another. The two former are situated in the basilar 

 area of the pons, the latter in the dorsal area (Figs. 87 and 88). 



The superficial transverse fibers are anterior in position 

 and form a thin compact layer constituting the anterior surface 

 of the pons (Fig. 87). They are not intersected by longitudinal 

 fibers ; but, otherwise, are like the deeper transverse fibers of the 

 pars basilaris poritis. 



Deep Transverse Fibers of Pars Basilaris. These form a 

 thick lamina posterior to the superficial transverse fibers and in 

 contact with the superficial lamina. They are intermingled with 

 longitudinal fibers from the bases pedunculi, viz., the pyramidal, 

 fronto-pontal, temporo-pontal and intermediate tracts (Figs. 

 87 and 88). In the meshes between the intersecting fibers is a 

 large mass of gray, matter, on either side, called the nucleus pontis. 

 The deep and superficial transverse fibers of the pars basilaris 

 pontis form the brachia pontis cerebelli. Their origin is found 

 in the opposite nucleus pontis (Klimoff). They continue the 

 indirect motor path from the termination of the fronto-pontal, 

 temporo-pontal and intermediate tracts in the nucleus pontis 

 to the cerebellar cortex of the opposite side. 



In connection with the superficial and deep transverse fibers 

 in the basilar part of the pons there should be mentioned an 

 independent strand, the fila lateralia pontis, which is situated 

 at the upper border of the pons and buried more or less in the 

 isthmian furrow between the pons and mid-brain. It is called 

 by Henle the taenia pontis. According to Sir Victor Horsley, it 

 rises from the nucleus pontis just ventral to the interpeduncular 

 ganglion, and, winding round the isthmus, enters the cerebellum 

 through the brachium conjunctivum. Its destination is probably 

 the nucleus dentatus and nucleus fastigii (Brain, Vol. 29, No. 113). 



The transverse fibers of the pars dorsalis pontis (Fig. 88) 

 compose a thin layer on the dorsum of the middle transverse 

 fibers, separating them from the formatio reticularis. This 



