BRACHIA OF THE PONS AND PROLONGATION OF THE CRUSTA. 461 



and farther downwards, as will be hereafter mentioned, by 

 fasciculi of the auditory nerve, which even constitute a very 

 considerable portion of its mass. 



THE BRACHIA OF THE PONS (BRUCKENARME, MIDDLE CRURA, 



PROCESSUS E CEREBELLO AD PONTEM) AND THE CONTI- 

 NUATION OF THE CRUSTA OF THE CEREBRAL PEDUNCLE 



(HlRNSCHENKELFUSS) . 



The fasciculi of the middle, like those of the superior, crura 

 of the cerebellum are indirectly represented in the projection 

 system of the cerebral hemispheres. 



Inasmuch as the fasciculi converging from the cerebral 

 cortex into the lenticular and caudate nuclei are larger than 

 the crusta of the crus cerebri proceeding from them, we must 

 regard all the fasciculi of the latter as an indirect prolongation 

 of the corona radiata, including those that do not reach the 

 spinal cord through the pyramids, but are lost to the projection 

 system in the pons. 



Whilst the crusta is broken up by the passage of the trans- 

 verse fibres of the pons (see figs. 250, 252, 254, Trs, Tr, 0, P), 

 into secondary fasciculi, these coincidently diminish in diameter 

 in consequence of the bundles which come from the crura 

 cerebri, splitting up still more finely, and part of their fibres 

 becoming connected with terminal cells (30 p long by 12 /t 

 broad). 



These nerve corpuscles, however, occur not only at the bor- 

 ders of the transverse sections of the secondary fasciculi of the 

 crus, where these are obviously in contact and connection with 

 the interlaced fasciculi of the pons, but they are found also 

 (1) within the area of the transverse section of the crus, which 

 seems to show that there is an intimate penetration of pyra- 

 midal and pontal fibres in the crusta of the cerebral pedun- 

 cle, and (2) within the purely transverse fibrous layers on the 

 surface of the pons, and in the deep layers of the anterior divi- 

 sion of the pons, where they likewise can only be subservient 

 to the interruption and augmentation of the fasciculi of the 

 cerebellum in some direction. 



If, in accordance with the appearances presented by the 



