282 



THE BRAIN OF QUADRUPEDS AND 



the development from them of numerous offshoots in the 

 form of * secondary fissures.' 



The * Longitudinal Pattern.^ This mode of arrange- 

 ment of some of the principal convolutions is well seen in 

 many of the Carnivora when the brain is looked at from 

 above, as in the Cat (fig. 96). When viewed from the 

 side the surface of the hemisphere may be seen, as 

 Marshall says, to be divided '' into four principal antero- 

 posterior convolutions, which seem to bend in simple 



curves around the up- 

 per end of the Sylvian 

 fissure, one above the 

 other, and pass con- 

 tinuously from the 

 anterior or frontal, in- 

 to the middle or pa- 

 rieto-temporal lobe." 

 This is well shown in 

 figs. 98-100. 



In the larger Feline 

 animals most of the 

 primary fissures pre- 

 sent short secondary branches. In the Fox and in the Dog 

 the fissures are more numerous still.* The Cerebrum is 

 also larger and narrower anteriorly, though in the Bear it 

 is again found to be more oblong. In the Seal this part of 

 the Brain attains the greatest relative size and complexity 

 known in the present group. f The Hemispheres are 

 unusually broad, and richly convoluted ; but a comparison 

 of the relative depth of the fissures enables the primary 



Fio. 95.— Right Cerebral Hemisphere of the Ele 

 phant, side view, much reduced. 



* This is move obvious in the Dog tlian in the Fox, owing to the 

 greater number, length, and depth of its secondary fissures. 



t Excellent figures of the brain of the Seal are given by Tiede- 

 mann in his ' Icones Cerebri ISimiarum.' Tab. 2, figs. 7, 8. 



