On the other hand, =the development of fat= in woman is much greater than in man. Bischoff investigated the relations between muscle and fat in man and woman, and found that in the entire body in the male there was 41·8 per cent. muscle and 18·2 per cent. fat; in the female 35·8 per cent. muscle and 28·2 per cent. fat. In the female two regions of the body are distinguished by a specially abundant deposit of fat, the breast and the buttocks, whereby both parts receive the stamp of extremely prominent secondary sexual characters. Upon this greater deposit of fat depends the softer, more rounded form of the feminine body; whilst the muscular system is less developed than in man. Man, on the other hand, is especially powerful in the head, neck, breast, and upper extremities. The contrast between the typical beauty of man and woman, respectively, is mainly explicable by the differences just enumerated. Woman’s =skin= is clearer and more delicate than that of man. More important is the fact that the blood of man contains a notably larger quantity of =red blood-corpuscles= (erythrocytes) than that of woman. Woman’s blood is richer in water. Welcker found in a cubic millimetre of man’s blood 5,000,000, and in the same quantity of woman’s blood 4,500,000 blood-discs. In correspondence with this, the hæmoglobin content and the specific weight of woman’s blood are both less than those of man’s. Since the red blood-corpuscles play a very important part in the human economy as oxygen-carriers, this sexual difference in the corpuscular richness of the blood is very important, and influences to a high degree the bodily organization of both sexes. =Larynx= and =voice= remain infantile in woman. Woman’s larynx is notably smaller than man’s. After puberty woman’s voice is, on the average, in the deep tones an octave, in the high tones two octaves, higher than man’s. According to the investigations of Pfitzner, the measurements of the =head= (length, breadth, height, circumference) are smaller in woman than in man. Woman’s skull remains, in respect of numerous peculiarities of structure, strikingly like the skull of the child.[21] This infantile quality of a woman’s skull, we must again point out, justifies =no= conclusion regarding the inferiority of woman. Schultze, when presenting these data for our consideration, rightly reminds us of the well-known fact that the man of genius is also frequently distinguished by infantile peculiarities. Woman’s skull is absolutely smaller than man’s; hence, of course, her brain is also absolutely smaller. Waldeyer gives as the mean weight of a man’s brain 1,372 grammes (44·12 ounces), and of a woman’s brain, 1,231 grammes (39·58 ounces); Schwalbe’s figures are respectively 1,375 grammes (44·21 ounces) and 1,245 grammes (40·03 ounces). In this connexion O. Schultze remarks: