Description of the cerebral hemispheres of an adult Australian male / by H.D. Rolleston.

  • Rolleston, Humphry Davy, 1862-1944.
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: Description of the cerebral hemispheres of an adult Australian male / by H.D. Rolleston. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    which by alcohol accounts for the greatly shrunken condition of brains preserved in spirit. Adding, then, 38 per cent, of tlie actual weight (31 ounces), the resulting weight of 43 ounces may be taken as representing, with a fair approach to accuracy, the weight of the brain at the time of death. So far very few Australian brains have been weighed: the average of six was found to be 41 ounces, two of these brains, it should be noted, are those of females.^ The weight of the brain as a racial character is a subject which has attracted a good deal of attention, and as the result of colossal tables, it may be taken that the average European brain weight in males is 49 ounces, the average weight of the negro race is about 44'3 ounces,^ which it will be seen is in excess of that of the primitive Australian. The age of the Australian was unknown, but his face, which is preserved in the anatomical museum of the University of Cambridge, shows no sign of age, but appears to be that of a man about the prime of life. If the convolutions of this Australian brain be compared with those of an average European brain the simplicity of the former is at once thrown into relief. The convolutions of the frontal lobe, which is connected with intellectual processes, are seen to have a marked antero-posterior arrangement, to be four instead of three in number, and to be separate, not to join each other at every turn and twist, as is so notably the case in the described brains of many eminent men, and generally in the more civilised nations. This simplicity of the frontal region is a point of importance, and may be considered as characteristic of a primitive brain. The frontal lobe being associated with higher faculties, it has been thought that the relation of amount of brain substance in front and behind the fissure of Eolando is of almost equal importance with the features mentioned above; but in this brain the relation of amount of brain substance in front and behind the fissure of Eolando was much the same as in an average European brain. It has also been thought that the prae-auricular development of brain is of importance from the same point of view, but this requires working out. * Dr. Thurnum (“On Weight of Brain,” “Journal of Mental Science,” April, 1866), gives the ratio of the cubic capacity of male Australian skulls to European as 85: 100. Now, the average brain weight of an European, according to Welcker, is 49 ounces, and assuming that the relation between cubic capacity of the skull and brain weight is approximately true, the brain weight of Australians would be 41'6 ounces. It will be seen that this deduction agrees fairly well with the result obtained in the brain under notice by adding 38 per cent, of the actual weight. ' Thurnum ; loc. cit.