Copc.J 010 [Marili Ui, 



cord, untl i)aralyzers of the motor or efferent nerves.* For the explanation 

 of tliese assertions, and for many other deeply interes'ing facts connected 

 with this subject, the reader is referred to other sources. 



Oil the Brain of Coryphodim. 



By E. D. Cope. 



(Read before tfu Am"rli'im Philosopldcal Society, March W, 1877.) 



Tlie character of the brain in Goryphodon being an important desidera- 

 tum, I endeavored to obtain a cast of the cranial cavity of a well preserved 

 skull of a C. ilephautopm, from the Wasatch l)eds of New Mexico. 

 The hard .sandstone matrix which tilled it, was removed with some diffi- 

 culty ; the more as its surfaces were indurated by a cement containing 

 much iron oxide. The osseous w^alls were found in a good state of preser- 

 vation. It was ascertained that there is a considerable foramen lucerum 

 posterius, but which is not nearly of sucii proportionate size as that in the 

 genus Tapirm. 



The form of the brain-cast thus obtained is very remarkable. Its distin- 

 guishing peculiarities are, il ) the small size of the cerebellum ; (2) the large 

 size of the region of the corjjora quadrigemina ; (8) the small size of the 

 hemispheres ; and (4i the enormous size of the olfactory lobes. 



There is in the cast a strong constriction in front of the medulla oblon- 

 gata on one side, which does not exist on the other side. It is uncertain 

 which represents tlie true form, as regards the lateral portion, but that 

 there was a step-like constriction across the base of the brain at this point, 

 tliere is no doubt. The medulla is very stout and wider than the hemis- 

 pheres ; it is depressed, and a protuberance on the inferior part of each 

 side has the appearance of the base of the eighth pair of nerves. The 

 region of the cerebellum is depressed and does not present in the cast a 

 distinct line of demarkation from the medulla. An indication of the vermis 

 is seen in a low longitudinal median protn1)crance. In front of this a trans- 

 verse shallow depression separates it from the middle l)rain. 



The region of the corpora quadrigemina is the most bulk}' portion of the 



cuals hiid been placed. After sitting a few minutes he l>eeanie completely para- 

 lyzed, and showed no Kifjns of life, except a deep sijih every fifteen or twenty 

 Kecoiids. {I^jiKlon Med. <inz., Oct. ISIC, quoted liy StiI16, 0/<. Oil. j). 324.) 



(5) Taylor states that in a case of suicide by nitrotin, tliat the per.son "becixme 

 iMsensit)le and ))owerl<'ss within a few seconds, and died in from three to five 

 niiiuit<-s; witliout oiivulsioMs." 



.\ reference to the experiments related in the text, will show the entire sinii- 

 larlly of tlie action of tobacco on man, to its action on llic lower animals. 



*Fr. <■. Woo i's Therapeutics, pp. 2S4, SIO, 341. 



