Free The Naked Ape by Desmond Morris Page B

pressing and caressing occur in abundance and far exceed anything found in other primate species. Also, specialised organs such as the lips, earlobes, nipples, breasts and genitals are richly endowed with nerve-endings and have become highly sensitised to erotic tactile stimulation. The ear-lobes, indeed, appear to have been exclusively evolved to this end. Anatomists have often referred to them as meaningless appendages, of ‘useless, fatty excrescences’. In general parlance they are explained away as ‘remnants’ of the time when we had big ears. But if we look at other primate species, we find that they do not possess fleshy ear-lobes. It seems that, far from being a remnant, they are something new, and when we discover that, under the influence of sexual arousal, they become engorged with blood, swollen and hypersensitive, there can be little doubt that their evolution has been exclusively concerned with the production of yet another erogenous zone. (Surprisingly, the humble ear-lobe has been rather overlooked in this context, but it is worth noting that there are cases on record of both males and females actually reaching orgasm as a result of ear-lobe stimulation.) It is interesting to note that the protuberant, fleshy nose of our species is another unique and mysterious feature that the anatomists cannot explain. One has referred to it as a ‘mere exuberant variation of no functional significance’. It is hard to believe that something so positive and distinctive in the way of appearance appendages should have evolved without a function. When one reads that the side walls of the nose contain a spongy erectile tissue that leads to nasal enlargement and nostril expansion by vaso-congestion during sexual arousal, one begins to wonder.
    As well as the improved tactile repertoire, there are some rather unique visual developments. Complex facial expressions play an important part here, although heir evolution is concerned with improved communication in many other contexts as well. As a primate species we have the best developed and most complex facial musculature of the entire group. Indeed, we have the most subtle and complex facial expression system of all living animals. By making tiny movements of the flesh around the mouth, nose, eyes, eyebrows, and on the forehead, and by recombining the movements in a wide variety of ways, we can convey a whole range of complex moodchanges. During sexual encounters, especially during the early courtship phase, these expressions are of paramount importance. (Their exact form will be discussed in another chapter.) Pupil dilation also occurs during sexual arousal and, although it is a small change, we may be more responsive to it than we realise. The eye surface also glistens.
    Like the ear-lobes and the protruding nose, the lips of our species are a unique feature, not found elsewhere in the primates. Of course, all primates have lips, but not turned inside-out like ours. A chimpanzee can protrude and turn back its lips in an exaggerated pout, exposing as it does so the mucous membrane that normally lies concealed inside the mouth. But the lips are only briefly held in this posture before the animal reverts to its normal ‘thin—upped’ face. We, on the other hand, have permanently everted, rolled-back lips. To a chimpanzee we must appear to be in a permanent pout. If you ever have occasion to be embraced by a friendly chimpanzee, the kiss that it may then vigorously apply to your neck will leave you in no doubt about its ability to deliver a tactile signal with its lips. For the chimpanzee this is a greeting signal rather than a sexual one, but in our species it is used in both contexts, the kissing contact becoming particularly frequent and prolonged during the pre-copulatory phase. In connection with this development it was presumably more convenient to have the sensitive mucous surfaces permanently exposed, so that special muscle contractions around the mouth did not have