144 



NATURE 



[Dec. 14, 1876 



the three gjri are marked off, the upper being broad and 

 the lower narrow. 



The tempore- sphenoidal lobe presents nothing remark- 

 able ; the parallel fissure is continuous and simple, run- 

 ning up behind into the angular convolution, where it is 

 cleft, one branch extending downwards parallel to the 

 lower part of the external parieto-occipital fissure, and 

 cutting off the middle temporo-sphenoidal gyrus from the 

 descending ramus of the angular and the second annec- 

 tent convolutions. The upper convolution is simple, the 

 middle is broader and more folded, the inferior is sepa- 

 rated by a well-marked sulcus from the middle. 



The first external annectent gyrus is seen issuing from 

 under cover of the operculum, and passing forwards and 

 inwards to the parietal lobule ; this is an approach to the 

 orang, in which the gyrus is norrrally superficial, and an 

 advance on the chimpanzee, in which it occurs only at 

 times. The second does not appear at all ; the third is 

 to be recognised nearer the lower margin of the hemi- 

 sphere and below the lower end of the external parieto- 

 occipital fissure, but the extension of tho parallel fissure 

 separates it superficially from the middle temporo-sphe- 

 noidal convolution ; below this the small fourth appears, 

 uniting the lower occipital and third temporo-sphenoidal 

 convolutions. 



Inner Surface of the Hemisphere. — The calloso-mar- 

 ginal fissure pursues its usual course and turns upwards 

 opposite the hinder end of the corpus callosum, sending 

 a branch backwards between the convolution and the 

 quadrate lobule ; it is interrupted opposite the anterior 

 extremity of the corpus callosum by a small gyrus, a very 

 frequent condition in human brains ; from it a few small 

 indentations pass, up into the marginal convolution. The 

 cdllosal convolution is simple : at the fore part there is a 

 hint of the longitudinal division which obtains here some- 

 times in man, and it is more broken up when it passes 

 under and is joined by the quadrilateral lobule. The 

 marginal convolution is larger and more divided, but both 

 of these are simpler than in the orang. The quadrate lobule 

 is divided into about four small gyri, and is much larger 

 than in the orang, where the calloso-marginal fissure 

 opens into the surface very near the parieto-occipital, and 

 the lobule is almost obliterated. The internal parieto- 

 occipital fissure does not join the calcarine below, so 

 that a distinct inferior internal annectent convolution 

 is present, and at the upper end the upper internal 

 annectent convolution can be seen coming out of the 

 fissure and joining the upper posterior angle of the 

 quadrate lobule. The calcarine fissure is usual, so also is 

 the fissure of the hippocampus. The occipital lobule is 

 divided into three gyri transversely by two furrows run- 

 ning the upper from the parieto-occipital, and the lower 

 from the calcarine fissures nearly across ; this is in marked 

 contrast with the arrangement of the human brain where 

 the gyri run from apex to base, being subject, how- 

 ever, to great variety. The gyri on the under surface 

 of the occipital and temporo-sphenoidal lobes cannot 

 be seen. 



The resemblance between this brain and the chimpan- 

 zee's is striking both in its shape and the arrangement of 

 the convolutions, so much so that Gratiolet's description 

 of the latter would serve also for many parts of the 

 gorilla's brain. The chief points of difference between 

 the two are mainly in favour of the gorilla, ^.^.,the greater 

 length and breadth of the frontal lobe, a greater develop- 

 ment of the middle and lower frontal and of the parietal 

 convolutions, especially of the supra-marginal lobule and 

 the appearance of the first external annectent gyrus. On 

 the other hand the chimpanzee appears to have some 

 advantage in the important point of greater vertical height. 

 On the whole, the comparison seems to indicate a deve- 

 lopment of the chimpanzee type of brain and to give it a 

 higher rank than that. 



In one particular character it approaches the orang, the 



partial appearance of the annectent convolution, but the 

 differences in shape, the more perfect operculum, the 

 lesser complication of tne frontal and occipital convo- 

 lutions and the greater symmetry far outweigh the resem- 

 blances and denote its proper position as with the chim- 

 panzee, although somewhat nearer the orang than that. 



Gratiolet placed the gorilla with the baboons by reason 

 of its elliptical form and the supposed want of develop- 

 ment of the frontal and great excess of the occipital lobes ; 

 but we see now that of all the anthropomorpha the gorilla 

 is charactcirised by the most extensive frontal lobe and 

 sm illest occipital ; in addition to which the richness of 

 the convolutions and the breadth of the frontal region 

 also separate it farther from the baboons than the chim- 

 panzfe. 



It is certainly open to great doubt whether this diminu- 

 tion of the occipital lobe is at all an ascensive step in the 

 cerebral conformation, in fact, the comparison of the 

 respective proportions in the bushwoman and the Euro- 

 pean points distincily in the opposite direction ; and it is 

 to be noticed that the great relative length of the frontal 

 lobe is entirely due to this dwarfing of the occipital, for 

 the proportion of the frontal to the parietal is no greater 

 in the gorilla than in the others ; and the highest type is 

 to be sought rather in the co-ordinate development of all 

 the lobes and not in the predominance of any one ; so 

 that regarded by this standard the gorilla's brain shows 

 one marked feature of inferiority. 



It should be remarked that Dr. Pansch, whose judg- 

 ment mubt carry great weight, is disposed to regard the 

 diver^jences from the chimpanzee as sufficient to establish 

 a distinct type of brain in the gorilla. 



In the comparisons above instituted, the brain of the 

 bushwoman so carefully and elaborately described by 

 Mr. Marshall in the Philosophical Transactions for 1864, 

 that of the chimpanzee described with photographs by the 

 same author in the Natural History Review for i86i, and 

 that of the orang in the same journal by Prof. Roileston 

 have been taken as standards, supplemented by reference 

 to the specimens in the Hunterian Museum. 



G. D. Thane 



MUSEUM SPECIMENS FOR TEACHING 

 PURPOSES 1 



I T is now generally admitted that a thorough and practically 

 -'■ useful knowledge of the form and other properties of natuial 

 bodies can only be acquired by an examuiaiion of such bouus 

 themselves. The difference between knoAijg a thing by de- 

 scription only and knowing it from personal acquain.a^ce n^ei 

 scarcely be insisted on. 



All teaching, therefore, of the physical properties, especially 

 the form, texture, colour, and relation to one another ol the 

 component parts of any natural object, whether organised or 

 inorganic, should be illustrated by reference to the object itself. 

 The more completely the student is enabled to examine ii, the 

 more thorough will his knowledge of it be. 



In the Department of Biology, which is that to which my 

 remarks must now be limited, v«.ry much valuabk and practical 

 teaching can certainly be given without the possession of a 

 museum or a single permanent preparation. The commoner and 

 easily accessible animals and plants furuish ma.erials for study 

 and demonstration, which, when done with, can be thrown away 

 and replaced as occasion requires. But it is often desirable to 

 preserve specimens for a considerable time or permanendy, 

 either on account of their intrinsic rarity, causing difficulties ui 

 procuring them when needed, or on account of the labour and 

 skill which may have been expended upon their proper display, 

 and which it is not desirable to have wasted. 



Hence the necessity for museums as most important adjuncts 

 in connection wiih all establishments for teaching biology. 



« Lecture at the Loan Collection of Scientific Apparatus, South Ken- 

 sington. July 26, 1876, by Prof. W. H. Flower, F.R.S., Conservator of tl»c 

 Museum of the Ruyal College of Surgeons of England. 



