THE MEDULLA OBLOXGATA. 



has tlu-n a givyish colour, whence the name tuberculum cinereum is 

 also given to it. 



The funiculus cuneatus is the prolongation of the posterior column 

 of the cord, and forms a swelling tuberculum cunmtum (fig. 262, ct}, 

 opposite the lower extremity of the fourth ventricle. 



The restiform body is the largest of the prominences of the medulla 

 oblongata, and appears to be the continuation of the funiculus of 

 Rolando and the funiculus 

 ! cuneatus. It inclines outwards 

 al> >ve, and enters the hemi- 

 sphere of the cerebellum, of 

 which it constitutes the inferior 

 peduncle. On the back of the 

 medulla oblongata, the inner 

 margin of this body forms the 

 lateral boundary of the lower 

 part of the fourth ventricle. 



The funiculus gracilis (pos- 

 terior pyramid) lies by the side 

 of the posterior median fissure, 

 and is the smallest of the parts 

 of the medulla oblongata. It 

 ends above in an enlargement 

 termed the clava (fig. 2b2, cl}, 

 which bounds the lower point 

 of the fourth ventricle. 



On the anterior surface of the 

 medulla oblongata there may be 

 seen, more or less distinctly in 

 different subjects, a set of fibres 

 crossing transversely to the res- 

 tiform body over the upper half 

 of the pyramid and the olivary 

 body. These are the superficial 

 arciform fibres. 



STRUCTURE. The fibres of 

 tin- several columns of the 

 spinal cord enter the medulla 

 oblongata below, where they 

 undergo a partial re-arrange- 

 ment and are partly continued onwards 

 cerebellum, being joined by other fibres which take their origin in 

 the bulb, and they partly end in the grey substance of the medulla 

 oblongata. The course of the fibres can only be shown to a very 

 small extent by dissection, and for the complete study of the 

 arrangement of the fibres, as well as of the grey matter, it is necessary 

 to examine sections of different parts of the medulla oblongata. 



Dissection. In tracing out groups of fibres in the hardened brain 

 the student will use the knife very little, but he will find that by 



Cuneate 

 fuiik-ulus 

 and 

 tubercle. 



Restiform 

 body. 



FIG. 262. MEDULLA OBLONGATA AND 

 PONS FROM BEHIND. 



fg. Funiculus gracilis. 



cl. Clava. 



fc. Funiculus cuneatus. 



ct. Cuneate tubercle. 



R. Funiculus of Rolando. 



rb. Restiform body. 



ct st. Auditory striae. 



ft. Fasciculus teres. 



sp. Superior peduncle (cut). 



mp. Middle peduncle (cut). 



*? Inferior peduncle (cut). 



to the cerebrum and 



Internal 

 structure of 

 medulla 

 oblongata. 



Dissection 

 to trace 

 pyramid. 



