352 PHYSIOLOGICAL Bfi&IBB, 



resemblance to the :i rnm Cement found in tho larger Ungu- 

 lata (compare the Horse's and Camel's brain). For in the 

 latter the " Sylvian figure" becomes relatively shorter the 

 larger the brain becomes, and it also gives off several 

 radiating branches, jusi as the larger Cetacean hrain gives 



off a group of deep radiating hranches (fig. 201,S.R.), some 

 of which actually open into the "Svlvian li-Min-.'' while 

 others merely seem to do so. 



Extending across the lateral convexity of the hemisphere 

 there is a series of large concentric arcuate sulci, the 



Fig. 201. (xf) 



...CER 



S.R. 



lowermost of which surrounds the radial hranches of the 

 " Sylvian fissure." 



It is customary to regard tln-se great arcs as the homo- 

 logues of (i) the ectosylvian, (ii) the snprusylvian, and (iii) 

 the corono-latd'al arcuate sulci respectively from helow up- 

 ward (lig. J()l, /. 2, and 3). If >uch le the case Uvhich 

 is hardly proliaMc), the reservation mii^t he made that it is 

 unu-ual in the ( 'arnivora and rngnl:il:i to find the ec 



sylvian sul-ii> M> exceptionally well developed a- it is 



this Cetacean, in which it so closely simulates the siipra- 

 sylvian sulcus of other mammalian Orders. 



