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short, and somewhat faint sylvian fissure visible lateral!}'. The four ojitic lobes 

 are placed in exactly the same plane with regard to each other, and the anterior 

 pair are divided by a somewhat obscure and diagonal fissure from the posterior pair. 

 The fact that these lobes are on the same level is worth noting, since it is often the 

 case that the anterior pair are above the level of the posterior pair. But in such 

 cases it is not at least always a question of ordinal distinction ; for while in 

 Dolichotis the four pairs of (juadrigemina corpora are npon the same level, those 

 of Sciurtis are so disposed that the anterior pair are above the posterior jmir. It is 

 also perhaps noteworthy that the line of division between the anterior and posterior 

 pairs of the corjiura quadrigemina are so slight ; the furrow is not well marked, 

 and, moreover, the distinctness of the two pairs of lobes is still furtlier obscured by 

 the fact that they do not rise in so conve.x a fashion in front of and behind the 

 furrow as in the brains of some other mammals. 



Intestinal Canal. 



Beyond stating that there is no caecum, Dr. Dobson gives no account of the 

 intestinal canal of Ceiitctes. I found that in the smaller specimen the whole canal 

 measured 4 ft. 3 in. Fifteen inches from the anus tliere was a sudden diminution 

 of calibre, the latter jiart of the intestine being narrower. I place provisionally 

 this point as marking the commencement of the " large " intestine. I say 

 " provisionally," because in the second and larger individual which I dissected 

 I could find no such break at a corresponding point. On the other hand, I did 

 find such a lireak at a distance of only eight inches from the anus. The latter 

 individual had a much longer gut, of which the total length was seven feet all but 

 one inch (i.e. S3 in.). 



Corresiwnding to the absence of complication in the gut itself, the arrangement 

 of the mesentery supj)orting it was found to be very simjile, more so than in a 

 Genet which I dissected for the purposes of comparison. The entire alimentary 

 tract was supported and tied to the middle dorsal line by a perfectly contiuuons 

 mesentery, which commenced with the commencement of the small intestine. The 

 only complication in the mesentery that I could discover was the presence of a 

 second mesentery attaclied to the o])posite side of the gut to that which bore the 

 chief mesentery, and which was independently attached to the mid-dorsal line of 

 the body wall ; this second mesentery only existed for the space of about three 

 inches. There was no break at the commencement of the large intestine, one 

 continuous mesentery forbidding any demarcation between the two sections of the 

 gut. Now the conditions which obtain in the Genet are slightly different. This 

 animal has a small caecum which has its own mesenteries, with the description of 

 which I am not concerned at present. But in addition to this the duodenum, where 

 it begins to bend upwards to the left, has a secondary mesenterial attachment to the 

 main mesentery, which supports it and the large intestine. For a space of about 

 two to three inches the duodenum is jirovided with two mesenteries, of which the 

 secondary one is inserted, not independently on to the dorsal body wall, but on to 

 the main mesentery ; this region is exactly opposite to the caecum and the com- 

 mencement of the large intestine. At this point the small intestine crosses over 

 the large. The condition which characterises Centetes seems to be obviously a more 

 simple condition than that which distinguishes the Genet. This is naturally in 

 accord with the relative jrosition in the system of the two groups, lusectivores and 

 Carnivores. 



