Читать книгу Old Age Deferred. The causes of old age and its postponement by hygienic and therapeutic measures онлайн

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If the bad qualities of the ductless glands are inherited, it is only logical to expect the same for the good qualities also. It stands on this basis that we may frequently find longevity in the same family. Longevity, as illustrated by the many facts adduced in this book from the field of clinical and experimental observations, is closely allied with a thorough performance of the functions of the ductless glands, especially of the thyroid gland; if these are in good condition, and especially if proper hygiene is also observed at the same time, longevity will follow. The good condition of the ductless glands is largely dependent upon a life based on hygienic principles, although when these glands are of the best quality they may stand a good deal and not degenerate so soon, even after excessive activity following injudicious or fast living.

But if a long life be dependent on a good state of the ductless glands and if the qualities of these are inherited—which cannot be doubted after the foregoing observations on heredity,—it must necessarily follow that longevity is inherited too, and this is a fact which can be proved by a large number of observations.