118 PHYSIOLOGICAL SERIES. 



in breadth at the broadest part. The specimen is still 

 largely covered by the dura and pia mat or. The ]>inl- 

 liko form of the hemispheres is very striking. Upon the 

 iH't side, i>art of the pallium has been removed to expose 

 the lateral ventricle, which is reduced to a narrow slit by 

 the great development of the corpus striatum. Openings 

 have been also made through the walls of the left optic 

 lobe and the cerebellum. The olfactory bulbs and tracts 

 have been removed. 0. C. 1318. Hunterian. 



D.137. The brain of a young Crocodile divested of its membranes. 

 The original description states that the brain is, " to ap- 

 pearance, made up of five parts; two, anterior, answering 

 to the cerebrum ; two behind these which answer to the 

 * nates and tostes ' ; the posterior, the cerebellum." The 

 transverse furrow upon the latter is very strongly marked. 

 The left half of the medulla has been removed. 



0. C. 1317. Ilunterian. 



D. 138. A longitudinal section of the head of a young Crocodile, 

 showing the brain in sagittal section from the left. The 

 brain is too small to show the anterior and posterior com- 

 missures, but upon the inner wall of the thalamencephalon, 

 towards the dorsal aspect, a roughened area is probably 

 the cut surface of the median (soft) " commissure," which is 

 found in certain Reptiles. The cavities of the right optic 

 lol>e and of the cerebellum and their connections with the 

 aqueduct of Sylvius and the fourth ventricle are very 

 cl.-arly shown. A marked protuberance into the optic 

 ventricle from the posterior wall of the lobe is due to the 

 at thi- spot of a large lateral nucleus, similar to 

 that found in Teleosts. The medullary flexure is strongly 

 marked. O. C. 1315. Hunterian. 



D. 139. The left half of the ^m.e head. The section in this case 

 passes slightly to the left of the mid-line. By this means, 

 although the olfactory peduncle is unavoidably removed, the 

 ventrirl.- <>}' the hemisphere and olfactory bulb, and the 

 relation of the latter to the nasal cavity are very clearly 



