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Show 142 MR. F. E. BEDDARD ON THE POUCH AND [Feb. 3, only to Prof. Flower's paper already cited and to a paper by himself which contains no description or figures of the Thylacine's brain. Gervais's description 2 is not taken from the actual brain, but from a cast of the interior of the skull which is figured 3 from above: he writes:-"The principal peculiarities presented by this cast consist in the preponderance of the posterior lobule of the hemispheres over the anterior, and, in consequence of this peculiarity, in the forward position of the Sylvian fissure. The anterior lobule is besides more compressed than in other Marsupials, and we have already seen in that fact a means of removing Thylacoleo from Thylacinus in classification. In the last-mentioned form the olfactory lobules are borne by a strong peduncle and they project notably beyond the anterior border of the hemispheres. As regards the hemispheres themselves, it appears that they are not without convolutions ; it is easy to distinguish one around the Sylvian fissure, and there is a marked transverse depression nearly median, although laterally it tends towards the posterior boundary. It marks the line of division between the two lobes, and may be considered as representing the fissure of Rolando. An anterior depression corresponds to the crucial sulcus, and there are traces of convolutions in tbe part which forms the posterior lobule." Since the Thylacine is an animal which is getting scarcer, I have thought that an attempt at a fuller description of the brain than is to be found in the memoirs cited might be acceptable, particularly if illustrated sufficiently. The press of other work unfortunately prevented me from studying the brain in the fresh condition, which would have been very desirable. Prof. Huxley 4 points out what erroneous conclusions may be reached by drawing inferences from the preserved brain only. But I am inclined to think that he has a little exaggerated the *^c* danger which is incurred from this proceeding. At any rate I can find no such alteration in the direction of tbe fissures in the brain of a Kangaroo which I sketched before and after preservation in alcohol. It is noticeable that the brains figured by Prof. Huxley, in which an alteration is to be observed, are of different sexes, though of about the same size. With brains prepared as carefully as they are in m y laboratory, the danger of alteration is reduced to a minimum. In the brain when viewed from above, the cerebral hemispheres, as in other Marsupials, do not only not overlap the cerebellum, but they only just reach it; they come nearer, however, than in the Wallaby (Halmaturus bennetti) or in the Koala (Phascolarctos) according to Mr. W . A. Forbes", or in the Opossum according to Owen6. This, 1 " On the Structure of the Erain in Marsupial Animals," Phil. Trans. 1837, pp. 87-96, pis. v.-vii. 2 "Memoire sur les Formes Cerebrales propres aux Marsupiaux," Nouv. Arch. Mus. t. v. pp. 229-251, pis. xiii., xiv. 3 PI. xiv. fig. 7. 4 " O n the Prain of Ateles paniscus," P. Z. S. 1861, pp. 247-260, pi. xxix. 5 "On some points in the Anatomy of the Koala (Phascolarctos cinercus)," P. Z. S. 1881, p. 191, fig. 3. B Phil. Trans, t. c. pi. v. fig. 6. |