Hardesty, Medulla Spinalis of the Elephant. 1 3 i 



The study of the specimen should begin naturally with the 

 observation of its macroscopic features. It will be remembered 

 that the author had no opportunity to observe the specimen 

 in situ. 



Owen (^^^^ calls attention to the fact that in the elephant 

 and the whale the cavum subdurale is relatively quite large, but 

 beyond mentioning the general difference between the dorsal 

 and ventral radices he gives no description of the medulla 

 spinalis. The reproductive organs proved of more interest to 

 him. 



Clarke ('58) in dealing with what at that time was con- 

 sidered "The intimate structure of the brain, human and com- 

 parative," notes, when touching upon the medulla oblongata, 

 that the "pyramids of the elephant, though not prominent, oc- 

 cur as long and tapering columns." 



Spitzka ('86) in a paper dealing with the comparative anat- 

 omy of the pyramidal tract, denies the elephant the possession 

 of "pyramids" individually and makes the general statement 

 that "the Proboscideae and Cetaceae are characterized by the 

 absence of pyramids in the medulla oblongata and by the con- 

 sequent exposure and natural approach of the olivary promi- 

 nences." His definition of pyramids, however, is confined to 

 appearances bearing that name in the human medulla oblongata; 

 i. e., to those columns which emerge at the inferior edge of the 

 pons, bordering the fissura anterior, and mesad to the olivae, 

 and which because of their peculiar shape in the human were 

 given the name "pyramids." Thus his denial of pyramids need 

 not deny pyramidal tracts. Yet in another sentence he states, 

 "The elephant and the porpoise agree in having no pyramid 

 tract — an expression probably of the physiological characters 

 of these animals." 



We shall see later that the elephant does possess not only 

 evident pyramids and pyramidal tracts but "crossed pyramidal 

 tracts," though the latter especially, differ considerably from 

 those of man. 



KopscH ('97) gives the only detailed description of the 

 medulla spinalis of the elephant so far found. It is the special 



