572 CORPUS OLIVARE. 



When cut through transversely as seen in fig. 221, page 565, 

 it presents a serrated appearance, like the corpus dentatum 

 of the cerebellum, fig. 224, page 577. By the facility with 

 which the corpus olivare may be turned out from its position, 

 as shown in the dissection of Mr. Solly, it appears to be a 

 ganglionic mass, intruded as it were between the ascending 

 fibres of the medulla, and .bulging them outwards. It forms 

 in many animals a large lobe for the origin of the pneumo- 

 gastric nerves, and its office is considered by Mr. S. as 

 exactly analogous in the human system. It appears to send 

 up no fasciculus of fibres to the brain, except those that origi- 

 nate in the interior of its cineritious vesicle ; the so called olivary 

 bundle of fibres of Gall and Spurzheim, which are extended 

 into the brain, coming from the lateral part or the antero- 

 lateral column, called by Cruvielhier the corpus innominatum. 

 This has already been described, page 570, as sending off 

 one band of fibres to join the corpus restiforme ; the other is 

 continued up, behind and around the corpus olivare,* lined on 

 its inner or central face with cineritious substance, and which, 

 enlarging as it ascends, and passing over the upper surface of 

 the pons varolii, is expanded into the optic thalamus. The 

 latter band thus forms in its course the anterior wall of the 

 fourth ventricle, and is brought into view by brushing away the 

 tuberculum cinereum, or gray matter of that ventricle. This 

 band constantly increasing as it ascends, has been called the 

 fasciculus cuneatus, (Burdach,) and fasciculus of reinforce- 

 ment, as it is much mixed up with gray matter on its inner 



* The corpus olivare was considered a ganglion by Spurzheim, Prochaska, 

 and Vic d'Azyr, though they did not attempt to determine its office. Solly con- 

 siders it the ganglion of the pneumogastric nerve, part of the fibres of which, 

 both from the result of experiments upon the ganglion, and from analogy with 

 its structure in the inferior animals, he believes to originate from it. He con- 

 siders it highly probable that it is a central point upon which is received the 

 organic sensations arising from the lungs, and from which emanates that 

 peculiar imperative power that the system of respiratory nerves conduct, and 

 by which they call the muscles of respiration into action, without the agency 

 of the will. This is very probably the case in regard to a portion of the fibres 

 of the pneumogastric, forming its reflex system of nerves ; other fibres in all 

 probability pass up into the brain, to constitute the cerebral sensiferous and 

 xnotorial portion of this nerve. 



