784 . REPORT— 1897. 



latter ; third, tliat in uncivilised man the proportion of male crania having a 

 capacity equal to the European mean, 1,500 c.c, is extremely small; fourth, that 

 though the capacity of the men's skulls is greater than that of the women's, there 

 is not quite the same amount of difference between the sexes in a savage as in a 

 civilised race. 



It may now he of interest to say a few words on the capacity of the cranium 

 in the large anthropoid apes. I have measured, by the method already referred to, 

 the capacity of the skulls of five adult male Gorillas, and obtained a mean of 

 494 c.c, the maximum being 590 c.c. and the minimum 410 c.c, the range of 

 variation being 180 c.c. Dr. Delisle found the old male Orang (Maurice),^ which 

 died a short time ago in the Jardin des Plantes, to have a capacity of 385 c.c, 

 whilst the younger male (Max) had a capacity of 470 c.c.^ The mean of eleven 

 specimens measured by him was 408 c.c, which is somewhat less than the 

 measurements of males recorded by M. Topinard and Dr. Vogt ; but it should be 

 stated that in some of Dr. Delisle's specimens the sex could not be properly dis- 

 criminated, and possibly some of them may have been females. The cranial 

 capacity of seven male Chimpanzees is stated by M. Topinard to be 421 c.c. 



The determination of the mass and weight of the brain as expressed in ounces, 

 and of the capacity of the cranial cavity as expressed in cubic centimetres, are 

 only rough methods of comparing brain with brain, either as between different 

 races of men, or as between men and other mammals. Much finer methods are 

 needed in order to obtain a more exact comparison. 



The school of Phrenologists represented in the first half of the century by Gall, 

 Spurzheim, and George Combe, whilst recognising the importance of the size of 

 the brain as a measure of intellectual activity, also attached value to what was 

 called its quality. At that time the inner mechanism of the brain was almost 

 unknown, for the methods had not been discovered by which its minute structure 

 could be determined. It is true that a difference was acknowledged, between the 

 cortical grey matter situated on the surface of the hemispheres and the sub- 

 jacent white matter. Spurzheim had also succeeded in determining the presence 

 of fibres in the white matter of the encephalon, and had, to a slight extent, traced 

 their path. The difference between the smooth surface of the hemispheres of the 

 lower mammals and the convoluted surface of the brain of man and the higher 

 mammals, and the influence which the development of the convolutions exercised 

 in increasing the area of the cortical grey matter, were also known. 



A most important step in advance was made, when, through the investigations 

 of Leuret and Gratiolet, it became clear that the convolutions of the cerebrum, 

 in their mode of arrangement, were not uniform in the orders of mammals which 

 possessed convoluted brains, but that different patterns existed in the orders 

 examined. By his further researches Gratiolet determined that in the anthropoid 

 apes, notwithstanding their much smaller brains, the same general plan of arrange>- 

 ment existed as in man, though differences occurred in many of the details, and 

 that the key to unlock the complex arrangements in man was to be obtained by 

 the study of the simpler disposition in the apes. These researches have enabled 

 anatomists to localise the convolutions and the fissures which separate them from 

 each other, and to apply to them precise descriptive terms. These investigations 

 were necessarily preliminary to the histological study of the convolutions, and to 

 experimental inquiry into their functions. 



By the employment of the refined histological methods now in use, it has been 

 shown that the grey matter in the cortex of the hemispheres, and in other parts of 

 the brain, is the seat of enormous numbers of nerve-cells, and that those in the 

 cortex, whilst possessing a characteristic pyramidal shape, present many variations 

 in size. Further, that these nerve-cells give origin to nerve axial fibres, through 

 which areas in the cortex become connected directly or indirectly, either with 

 other areas in the same hemisphere, with parts of the brain and spinal cord 

 situated below the cerebrum, with the muscular system, or with the skin and 

 other organs of sense. 



' Nbuvelles Archives du Museum d'Histoire natvrelle, 1895. 

 ^ The stature of Maurice tvas 1 m.-40 ; that of Max 1 m.'28. 



