THE testis, the organ which produces the male germ cells or spermatozoa, elaborates also a hormone which is responsible for the secondary sexual characteristics that appear in man. If deprived of this organ, man fails to grow hair upon his face and body, and the voice remains high-pitched and ‘unbroken,’ owing to under-devc/lopment of the larynx. Eunuchs, too, are invariably fat.

Voronoff has claimed that many of the manifestations of

old age are due to the fact that the testis runs out of secretion and fails to keep the body in good repair. He grafted the testes of monkeys into patients who were growing old and claims that they became rejuvenated. Whether his results are as good as popular opinion would lead us to suppose is uncertain, but it would seem to be a dangerous experiment, for it is, as it were, driving too hard a dying horse. The last years of life may be made more exciting and the patient may feel younger, but the machine will probably run down more rapidly and life come to an end sooner and in a more spectacular manner.

It must not be supposed that the ductless glands work separately and independently of one another. Each affects the others, and any upset in one will lead to corresponding upsets in the rest. A balance is normally effected between all the hormones circulating in the blood, and on this balance our well-being depends. Some people place disturbances of the ductless glands as the cause of many of our obscure conditions of ill-health, others say that they are responsible for all the differences in personalities and psychical qualities that exist between each one of us. However much truth there is in these theories, one thing is certain and that is that we know very little of their relationships one to another, that much will be found out in the next few years, and that meanwhile we should be wary in upsetting the balance by dosing people with products of the ductless glands without adequate cause.