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 ^ is not taken from the actual brain, but from 

 a cast of the interior of the skull which is figured ^ 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 classi- 

 fication. In the last-mentioned form the olfactory lobules are 

 borne by a strong peduncle and they project notably beyond the an- 

 terior border of the hemispheres. As regards the hemispheres them- 

 selves, 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 the 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 de- 

 sirable. Prof. Huxley * 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 

 danger which is incurred from this proceeding. At any rate I can 

 find no such alteration in the direction of the 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 my 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 

 {Ralmaturus bennetti) or in the Koala (Phascolarctos) according to 

 Mr. W. A. Forbes % or in the Opossum according to Owen". This, 



1 " On the Structure of the Brain in Marsupial Animals," Phil. Trans. 1837, 

 pp. 87-96, pis. v.-vii. 



^ "Memoire sur les Formes Cerebraies propres aux Marsupiaux," Nouv. Arch. 

 Mus. t. T. pp. 229-251, pis. xiii., xiv. 



3 PI. xiv. fig. 7. 



* " On the Brain oi Ateles paniscus," P. Z. S. 18f51, pp. 247-260, pi. xxix. 



^ " On some points in the Anatomy of the Koala {Phascolarctos cinereus),^' 

 P. Z. S. 1881, p. 191, fig. 3. 



^ Phil. Trans, t. a. pi. v. fig. 6. 



