Cancer
No man will knowingly marry a woman, and no woman will marry a man, afflicted with cancer. However, this question often comes up in cases where the matrimonial candidates are free from cancer, but where there has been cancer in the family.
Cancer is not a hereditary disease, contrary to the opinions that have prevailed, and, if the matrimonial candidate otherwise is healthy, no hesitation need be felt on the score of heredity. The fear of hereditary transmission of the disease has caused a great deal of mischief and unnecessary anxiety to people. Scientifically conducted investigations and carefully prepared statistics have shown that many diseases formerly considered hereditary are not hereditary in the least degree.
Should it, however, be shown that in one family there were many members who died of cancer, it would indicate that there is some disease or dyscrasia in that family, and the contracting of a marriage with any member of that family would be inadvisable.
Exophthalmic Goiter (Basedow's Disease)
Exophthalmic goiter is a disease characterised by enlargement of the thyroid gland, protrusion of the eyeballs, and rapid beating of the heart. The disease is confined almost entirely, though not exclusively, to women, and I should not advise any exophthalmic woman to marry; neither should I advise a man to marry an exophthalmic goiter woman. It is a very annoying disease, while sexual intercourse aggravates all the symptoms, particularly the palpitation of the heart. The children, if not affected by exophthalmic goiter, are liable to be very neurotic.
Simple goiter, that is, enlargement of the thyroid gland (chiefly occurring in certain high mountainous localities, such as Switzerland), is not so strongly dysgenic as is exophthalmic goiter. Still, goiter patients are not good matrimonial risks.
Of course, there are always exceptions. I know an exophthalmic goiter woman who brought up four children, and very good, healthy children they are. But in writing we can only speak of the average and not of exceptions.
Obesity
Obesity, or excessive stoutness, is an undue development of fat throughout the body. That it is hereditary, that it runs in families, there is no question whatsoever. And, while with great care as to the diet and by proper exercise, obesity may, as a rule, be avoided in those predisposed, it none the less often will develop in spite of all measures taken against it. Some very obese people eat only one-half or less of what many thin people do; but in the former, everything seems to run to fat.