Palla Ákos szerk.: Az Országos Orvostörténeti Könyvtár közleményei 37. (Budapest, 1965)

Tóth Tibor: The Variability of the Brain-Weight by Homo

agrees to those of the normal, edematous and atrophied categories (Table 3.). Otherwise, atrophia cerebri significantly reduces the weight of the brain in both males and females (50—100 grams) (Table 3), and the difference is more significant than in connection of the normal and edematous categories. In other words, the tendency of atrophia cerebri to reduce weight is greater than that of oedema cerebri to increase it. Since apoplexia-, and atrophia cerebri are represented by a very small number of cases (Table 1), sexual dimorphism was analyzed mainly for the normal and edematous categories. Intersexual differences are also clearly expressed by the weight differences of two categories covering a considerable number of cases. Let us note that sexual dimorphism—as expressed by the weight of the brainis significantly reduced during the process of aging. Especially when analyzing the variability of the weight of the brain in the major age groups of the normal category (1,110 males and 1,022 females) it may be asserted thet while it is intersexually 133,5 grams for the Maturus, it is only 75,4 grams for the Hypersenilis, i. e., at the end of old age the sexual dimorphism of the brain is quantitatively reduced approximately by half (Table 2). Perhaps this quantitative reduction expresses the neutralization of dimorphism during old age(?) It is a no unessential question whether the brain reaches its maximum weight until Adultus, or continues to grow during adulthood? If the averages of the main age group (Table 2.) are analyzed, the reply is in the negative. On the other hand, from the detailed analysis of the pertinent cases, it may be discovered that the brain reaches its maximum weight for females by the first half of Adultus (between 20 and 30 years), while for males by the second half of Adultus (30—40 years) (Table 3.), Thus the maximum increase of the weight of the female brain generally ends ten years sooner than that of males. This intersexual heterochronia is likely to be a manifestation of sexual dimorphism. Nevertheless a general assumption cannot quite be made on this basis because the data on Adultus from Roessle and Roulet differ from mine (Table 4). This may be related to the difference between the number of pertinent cases (Table 4) and it is possible that the reduction of cases on account