TEM, PHYSIOLOGY OF, VOI. iii. p. 782. s.) No doubt, however, can be entertained that the mind is intimately connected with the procre ative faculty, and that the brain controls and animates the desire for sexual enjoyment. An affection of the brain, or the mind, as sudden disgust, arrests the secretion of the testicles and extinguishes all desire as quickly and effectually as a strong mental impression stops the secretion of the gastric juice, and takes away all appetite for food. The influence of the brain on the reproductive function is well illustrated by the occasional effects of injuries of the head. Hildanus mentions the case of a man accused of impotency by his wife, who sued for a divorce. Nothing external was de fective ; but the man stated that eight years previously he had received a blow on his head by a stick. From that period, " confitebatur penem erigi non posse." t Dr. Fisher relates the case of a gentleman who, while looking out of the window of a railway carriage, which at that moment encountered a violent collision, received a blow on the head and neck, by which he was stunned. On the se cond day after the accident he complained of a numbness in his right arm, and experienced difficulty in passing his urine. In the course of two weeks he was able to leave his bed, and walk in the street ; but his vision was defective. Between the fourth and fifth week after his injury he made the discovery that he had lost the desire and physical power for sexual intercourse, and that no amorous sentiment, or the approach of a female could excite it. Under appropriate treatment the bladder gradually recovered its power, and his vision became perfect ; but the numbness of the right arm continued, and the generative functions remained partially impaired. His mental powers, particularly his memory of events, were also for a time seriously affected.$ Dr. Gall mentions that at Vienna he was con sulted by two officers who had become im potent in consequence of blows from fire-arms which had grazed the napes of their necks. One of the officers recovered his powers by degrees, married, and became the father of several children.* When treating of Atrophy of these glands, I shall have occasion to mention cases in which the genital function has been perma nently annihilated, and complete wasting of the testicles has resulted from injuries of the head. In respect to the mode in which these organs are called into action, they bear consi derable analogy to the lachrymal, salivary, and mammary glands, in which secretion is excited both by the influence of the mind and by me chanical contact or local irritation of the ex tremity of the excretory duct, the glans penis holding the same relation to the testicle as the mucous membrane of the mouth does to the salivary glands, or as the nipple does to the mamma.
The influence of the testicles and brain upon each other appears, as has been already observed, to be reciprocal ; for not only may desire be aroused by local irritation and ex citing the testicles to secrete, but the passion itself never arises when these glands are re moved before puberty and is extinguished by their extirpation afterwards. Nothing, indeed,
illustrates more forcibly the intimate relation which the functions of the testicles bear to the mind and character of the individual, and the general organisation of the body, than the effects of castration. When it is performed in early life, the changes characteristic of puberty never ensue. There is a deficiency of the beard ; the muscles do not acquire the manly tone and vigour ; the areolar and adipose tissues abound ; the voice retains the high and clear tones of infancy ; and the mind remains deficient in energy and strength. When the testicles are removed after the period of puberty, the eunuch loses in part, though not entirely, his former masculine character. His beard grows less abundantly ; his voice becomes shrill; and there is di minished energy and vigour in all his senti ments and actions. These changes in the con stitution, as well as the loss of the sexual instinct which occur in men thus degraded, do not immediately succeed the removal of the testicles, but take place gradually ; and there are well-attested cases in which desire has been experienced, and connection with emis sion accomplished many months after the loss of these organs. This shows that the passion is not solely dependent on the secretion of semen, though it invariably declines when the power of procreation becomes lost. The emis sions in such cases are imperfect and fruitless, consisting merely of the secretions of the vesiculm seminales and prostrate. The testi cles not being parts essential to life, are sub ject to different laws from those which re gulate the actions of the vital organs. Their functions may be suspended, or they may remain in abeyance for an indefinite period without injury to the glands or any material effect on the constitution. In persons of recluse and studious habits the functions of these organs often continue dormant for years. Like the mamma: in the unmarried female, though inactive, they remain sound and competent for secretion when duly ex cited and called upon to exercise their func tions. It often happens that the passions are excited without an opportunity being afforded for their gratification. Under these circum stances the testicles become encumbered with secretion which would prove injurious to them were they not relieved by occasional nocturnal emission, or ejaculations of the semen under the influence of dreams during sleep, which appear to be a salutary provision to obviate the inconveniences which might result as well from ungratified desires as from an accumulation of semen in the ducts.