The breasts and the developed hips are characteristics of women and are indications of functional effectiveness as well as sexual allurement. Another prominent sexual character which belongs to man, and is not obviously an index of function, is furnished by the hair on the face. The beard may be regarded as purely a sexual adornment, and thus comparable to the somewhat similar growth on the heads of many male animals. From this point of view its history is interesting, for it illustrates the tendency with increase of civilization not merely to dispense with sexual allurement in the primary sexual organs, but even to disregard those growths which would appear to have been developed solely to act as sexual allurements. The cultivation of the beard belongs peculiarly to barbarous races. Among these races it is frequently regarded as the most sacred and beautiful part of the person, as an object to swear by, an object to which the slightest insult must be treated as deadly. Holding such a position, it must doubtless act as a sexual allurement. "Allah has specially created an angel in Heaven," it is said in the _Arabian Nights_, "who has no other occupation than to sing the praises of the Creator for giving a beard to men and long hair to women." The sexual character of the beard and the other hirsute appendage is significantly indicated by the fact that the ascetic spirit in Christianity has always sought to minimize or to hide the hair. Altogether apart, however, from this religious influence, civilization tends to be opposed to the growth of hair on the masculine face and especially to the beard. It is part of the well-marked tendency with civilization to the abolition of sexual differences. We find this general tendency among the Greeks and Romans, and, on the whole, with certain variations and fluctuations of fashion, in modern Europe also. Schopenhauer frequently referred to this disappearance of the beard as a mark of civilization, "a barometer of culture."[151] The absence of facial hair heightens æsthetic beauty of form, and is not felt to remove any substantial sexual attraction.