There is a tendency for pronounced types of any diathesis to grow weaker and weaker until unfit to reproduce; then they die out.

As stated often before, disease is not transmissible, but enervation is, Enervation means lost power of resistance, and when resistance is low, the influences which lower it find the high-bred diathetic easy prey, so to speak.

In breeding lap-dogs, the lower their nerve energy and the less, their resistance, the more popular they are among dog fanciers. The nearer death from fatty degeneration the stock at the stock shows is, the more it is admired and the greater is the premium.

One day years ago I was crossing Boston Commons. Moving along in front of me, at a snail's pace, was a woman far gone with fatty degeneration. When I was within ten steps of heir, she turned and said in a lackadaisical voice: "Darling, do you want mamma to wait for you?" I looked in the direction of her eyes, and saw an exophthalmic dog, whose weight certainly contrasted with that of its "mother," for she probably weighed two hundred, and her offspring could not have exceeded six to nine ounces.

The dog's breeding had left it with scarcely enough nerve energy to stand on its legs. It had eyes, but it saw not, and it had life, but it lived not. It was a case of nervous diathesis. It was bred almost out of existence.

Children may be born of parents who come from parents with strong, well-marked diatheses--with low resistance to influences which pervert nutrition--and if the diathesis favors tuberculosis, that disease will develop; if the diathesis is that of gout, the children will develop rheumatism and other gouty affections.

Children of tubercular diathesis, when bred down until they are very enervated, have but little resistance, and when they are abused in a way to pervert nutrition, they develop some form of tuberculosis. All they need to start the morbid process is to be vaccinated with cowpox, which is a bovine type of syphilis. Just what the difference is, the highest medical authorities do not know; the only apparent difference being that one develops in the human being and the other develops in the cow.

In a pronounced type of scrofulous diathesis, vaccination is all that is needed to set up a tuberculous or syphilitic morbid process that will be pushed on by wrong life to destruction of health and life while the victim is quite young.

Vaccination may start a morbid glandular derangement that will favor the development of all the catarrhal diseases peculiar to child-life.

Of course, infections from toxin absorption in the intestine are common to children of diathetic type.

Children from a long line of ancestry favoring the development of the scrofulous, tuberculous, or syphilitic diathesis are weaklings, with flabby muscles, who develop adenoids and enlarged tonsils early. They develop skin diseases of an impetigo variety, and their lymphatic glands are very prone to take on inflammatory enlargements.

There are many fatal diseases developing in these children before and at puberty because their resistance is low and they are subjected to the same disease-producing habits as those from whom they inherit their type of health.

According to Darwin, this is the way the unfit are made to disappear.

A dyscrasia or diathesis is the sum of erroneous living practiced through generations. Diseases peculiar to a diathesis are not long in developing when the strain is pure and inbred; but where a beautiful tuberculous girl, with long, silky eyelashes and well-rounded body and limbs, compels an Apollo of the sanguine, vital temperament to fall in love with her, the tuberculous strain is diluted and the half-tuberculous children are given power to live; whereas, if the girl had attracted a young man, like herself, of tuberculous diathesis, the children of such a union would be born to die early.