IX. Comparative Study of the Epiphysis and Roof of the 



DlENCEPHALON. 



By A. D. Sorensen, A.B. 



Fellow in Neurology. 



The object of the present work has been to present, in 

 addition to the original matter, a more complete historical ac- 

 count of the studies of the epiphysis and the roof of the dien- 

 cephalon than has yet appeared. For this purpose the original 

 articles have been largely reproduced. 



To enhance the value of the appended bibliography it has 

 been thought best to include the names of investigators whose 

 papers have not been available, as well as those here presented. 



Historical Account. 



Brandt 1 (8) described the skull of Lacerta agilis as follows : 

 Occipital plates, 4 ; seldom only 3 ; the two most median situ- 

 ated behind one another, the smallest, the upper, larger, regu- 

 larly 5-cornered, most median, with a round sunken spot, and 

 he adds in a foot note : marking a special glandular spot. The 

 external marking on the surface of the head is not represented 

 in his drawing of L. agilis, (fig. A. Taf. XIX), but his descrip- 

 tion shows that he recognised the presence of an internal modi- 

 fication corresponding to the specialized scale. 



Milne Edwards 1 (77) and Duges 1 (/^) both figure the ex- 

 ternal modifications in certain lizards, but neither, strangely, 

 makes the slightest mention of it in his descriptions of the 

 animals. 



Reissner (75-' 51) first represented the pineal projection 

 correctly and 



Reichert (7^-61) called it the recessus pinealis v. supra- 



'Fide Spencer. 



