Note D — Chapter VII · THE FUNCTION OF THE MALE GENERATIVE ORGANS

Explanatory remarks: When a voluptuary thought originates in the centre of voluptas 11, it is transmitted by fibre 12 to the vasodilatory centre 4 in the medulla oblongata, hence by fibre 14 in the spinal cord to the centre of erection 16 in the lumbar part of the cord; hence through the nervi erigentes 17 to the genitals at the periphery 10, where it responds by an erection. The excitation of the erection is then, if strong enough, transmitted through the centripetal or sensory nerve 9 to the centre of ejaculation 7; hence again through the centrifugal ejaculatory nerve 8 to the periphery, where ejaculation takes place.

When an excitation originates at the periphery 10, as in sleep, it is transmitted through the sensory nerve 18 to the centre of erection 16, and through nerve 15 to the vasodilatory centre 4; hence back to the periphery by the nerves 14 and 17, after the inhibitory nerve 13 has been paralyzed. The excitation of the erection is then transmitted, as previously described, through nerve 9 to centre 7 and nerve 8 to the periphery where ejaculation takes place. In either case the excitation of the ejaculation is then carried through the sensory nerve 5 to the centre of libido 3 and is there experienced as a pleasurable feeling.

When the centre of erection 16 is directly irritated, for example, by electricity, after the spinal cord has been severed, the stimulus is directly transmitted through nerve 17 to the periphery 10 to respond with erection. The same road is taken by the excitation of the centre of erection 16 during sleep.

In spermatorrhoea the stimulus at the centre of voluptas 11 is directly transmitted through nerve 6 to the centre of ejaculation 7, hence through nerve 8 to the periphery 10, and ejaculation takes place without erection.