238 



PHYSIOLOGICAL SERIES. 



Hence we find in the case of the Cat's brain tbat the 

 rhinal fissure (which is the line of demarcation upon the 

 lateral aspect between the essentially olfactory pyriform 

 lobe and the neopallium) is placed very low down on the 

 lateral and partly on the basal surfaces of the hemisphere. 

 [See the diagram of the Lion's brain, fig. 116.] 



A short sulcus, generally known as the " Sylvian fissure," 

 springs from the junction of the anterior and posterior 

 rhinal fissures. This "fissure" does not correspond to that 

 called " Sylvian " in the Bears, and it has moreover a 

 significance very different to the Human Sylvian fissure. 



Fig. 116. 



SULC.SUPRAS. 



SULC . LAT. 



SULC. POSTS. 



SULC. ANS. 

 SULC.CR. 

 SULC. COR. 



SULC. LAT. P. 

 I 



SULC.PROR. 



OLF. BULB 



SULC. ORB. 



SULC.ECTOS A. 



Hence it will conduce to accuracy and clearness if \\e i all 

 it the "Feline Sylvian fissure." It may be compared to 

 that already noticed in the brain of the Three-toed Sloth. 



In the left hemisphere the anterior lip of this fissure ha- 

 been cut away, but there is no distinct area of cortex sub- 

 merged in the fissure such as Holl describes (Arch.f. Anat. 

 u. Entwick. 1899, p. 229). At the same time it will be 

 noticed that the lower part of the fissure cuts into the 

 hemisphere very obliquely, so that the anterior lip overlaps 

 the posterior lip. In the larger Felidse this becomes much 

 more accentuated, so that a relatively largo area of tin- 

 posterior lip becomes overlapped by the anterior lip. In 

 Mich forms, and sumtimes also in the Cat, a .short 



