A very specific form of impotence, called koro, occurs in China and South-East Asia. The word is of Malay origin and means the head of a tortoise. It describes a psychiatric syndrome, in which the usually older patient becomes convinced that his penis is shrinking and will disappear into his abdomen (like a tortoise’s head), […]

The fact that in the distant past there were so many different ways of delivering sperm cells — with some male animals surpassing others by developing methods of getting as close as possible to the ovum — led to the evolution of the penis. It was to play a crucial role in reproduction. There are […]

One of the first people to study the penis and erection scientifically was Leonardo da Vinci. The most incisive mind in human history took a keen interest in the sexual organs. In his view the genitalia both of the man and of the woman were so repulsive that, were it not for the beauty of […]

Phallus is the name given to the erect penis as a symbol; most people associate the term penis with something or someone else, for example their bearded biology teacher from school or sex education manuals. This is not to say that the sex education manuals of, say, the 1960s were bad books — on the […]

Impotence means literally the inability to perform sexual intercourse, though the word is often used in a disparaging sense, implying help­lessness. Impotence is probably one of the best kept bedroom secrets and, at least for those affected, one of the most shameful. Fortunately a euphemism has been devised: erection problems or, even more useful, erectile […]

The ductus deferens, between 30 and 40 cm long, links the epididymis with the urethra. Immediately before the actual ejaculation rhythmic contractions take place in the smooth muscle tissue of the wall, pro­pelling the sperm cells towards the ampoule and the urethra. This muscle-lined tube with a diameter of between 3 and 4 mm can […]

The sperm-forming tubes in a testicle discharge into a kind of transit depot. Between six and eight ducts lead to the epididymis. In the epi­didymis those ducts merge into a single tube. While the sperm-forming tubes in a testicle have a combined length of 250 metres, an epididymis is a duct of approximately 6 metres […]

A dentist about to start root canal work on a woman suddenly feels her hand firmly grasping his testicles. As he stares at the women open­mouthed, she says with a smile: ‘Let’s promise not to hurt each other!’ Pain in the testicles is excruciating, but hard to understand even for doctors. The fact is that […]

Back to temperature regulation by the scrotum: the skin of the scrotum is characterized, like that of the eyelids, by the absence of subcutaneous fat, the presence of many tiny blood vessels, and a layer of muscle directly under the skin. Fat insulates too well, which does not help the ability to react rapidly to […]

The degree of hirsuteness and the smell of the scrotum vary — a topic that was raised as early as the 1870s in the work of the American feminist novelist and campaigner Lois Waisbrooker (1826-1909). Some of today’s racy pulp novelists, one feels, should have been made to study Erica Jong’s Fear of Flying (1974) […]