Tuberculosis (“the white death”) is from every standpoint a social danger more serious than syphilis. The father, as in syphilis, can infect the mother, but sterility is much less likely. As has already been shown in the chapter on heredity, plural and quickly repeated birth are common in tuberculous families. The tuberculous diathesis (or “habit,” as Weismann calls it) was very early observed in the United States. Nearly seventy years ago W. P. Dewees, of Philadelphia, pointed out its frequency and its early observation by the Greek and Roman physicians. He cites a case illustrative of the extent and uniformity of diathesis in a very numerous family. This predisposition arose on the side of the mother, though she lived herself to the age of forty-three, a period much exceeding that of any of her children, with the exception of a son, who died in his forty-fifth year. This lady bore twenty-three children without being able to suckle any but the two first. The males much exceed the females in number, yet there did not appear to be any exception to their favour in the transmission of the phthisical taint, except that they attained in general a greater age before they died. Some died about puberty, others at manhood or womanhood; but all, with the exception just stated, under thirty. The disease was never very rapid; they generally complained from one to two years before they died. The men had a healthy, even in some instances an athletic, appearance until the disease became open and decided. In their growth and stature they altogether resembled the father, who was not only a remarkably stout man, but lived beyond the eightieth year. The females, who passed puberty (two in number) were rather stout women, while the mother was both delicate and small. This family lived in the country, was very wealthy, and always accustomed to the various means generally found successful either in destroying the predisposition or lessening its influence, yet in no one instance in this family were they successful, though the open form of the disease was retarded perhaps in all. The females died the earliest.[168]
The blood vessel system is affected as regards development in such families. The heart is often diminutive; the right ventricle is exaggerated. Two great types of degenerate constitutions are produced in children of the tuberculous. One of these may well come under De Giovanni’s category of the torpid. The victim is usually coarse-featured and coarse-skinned, with peculiarly unstable mentality; slowness of comprehension is combined with power of continuity of thought; at times mental apathy alternates with quickness of perception. Decided exaggeration of the lymphatic system (connected with utilising of material elsewhere than at the point where it has been rendered unfit) with deficient function occurs, resulting in fitting a soil for germs. In other respects the torpid resembles the second type, the erethistic (nervously fussy type) of De Giovanni. This is generally characterised by the presence of a clear complexion, a fine skin, and features well cut and often beautiful. The lips are red and the teeth pearly white, though liable to early decay, and the eyes are large and full, the pupil being widely dilated and the white of the eye beautifully clear. The eyelashes are long, curved and silky, and the blue veins show distinctly through the clear thin skin. The bones are light, the hands and feet well formed, the stature often tall, and the whole figure slightly and gracefully built. The erethists generally remain spare, and have a strong dislike to fatty food. They are vivacious and excitable, and the intellectual faculties are often highly developed. At an early age they show marvellous activity. The regularity with which such precocious tubercular children die has given rise to proverbs anent exceptionally clever children that they are “too wise to live long.” Wanting in stamina, they are incapable of prolonged exertion either of mind or body, and break down under conditions which would not prove injurious to the healthy. They are continually taking “cold,” and are prone throughout life to affections of an inflammatory character. Multiple and frequent pregnancies occur. The children, deficient in vitality, are carried off in numbers during infancy by convulsions, brain fever, water on the brain, exhaustion, diarrhœa, teething, and other ailments, or they succumb at the second detention or at puberty. A small proportion reach maturity. Few live beyond thirty-five or forty years of age. However brilliant intellectually, they are equally emotional, impressionable, and impulsive. There is a marked absence of mental stability. They are suspiciously capricious. The great secreting and eliminating glands undergo with peculiar frequency the perversions already described.
Neuroses and psychoses are peculiarly frequent in childhood and youth. The degenerative power of tuberculosis is not always due to the influence of the germ, or even of the toxin produced by it, but to the state of nerve weakness resultant on the disorder. The victim of tuberculosis (especially if affecting the lung) is a suspicious, yet hopeful, nervous invalid, whose functions are irregularly performed and who is therefore likely to leave scions with greater defect, especially as the maternal factor, either through infection or worry, can hardly escape being weakened. Tuberculosis attacks the bones of the offspring, especially the spine and hip-joint, but the victim of these last frequently regain health after apparent recovery from the local disease through surgical procedures. If the victim of the hip-joint disorder be of the erethist type marriage is not unlikely. Despite the deformity produced by spine disorder, popular superstition as to the “good luck” of a hunchback leads to marriage among the working class. Monetary and social considerations effect the same result among the wealthy classes. Here deformity does not prevent marriage, but predisposes to sterility through birth difficulty.
The influence of syphilis is, in a general sense, the same as that of tuberculosis, except that by reversing the principle of individuation it leads to greater sterility. Furthermore it exhibits greater tendencies to revert towards health, and yields (even in the inherited form) more to medicinal treatment. The inherited form at times presents itself in two types closely simulating those due to tuberculosis. Like the bacillus of tuberculosis, the syphilitic germ attacks every structure and organ of the body. Its reversal of the principle of individuation, causing excessive cell formation, produces more decidedly demonstrable effects. As syphilis is more apt to attack the central nervous system than tuberculosis, it would seem that it is a greater race-deteriorating factor. The excessive tendency to cell formation, however, produces impotence in man, sterility and abortion in woman. There are very good reasons for believing that the race is becoming immune to syphilis, and that this disease will disappear. Its greatest race-deteriorating effect is in preparing the soil for tuberculosis and other infections and contagions.
The influence of contagions and infections on degeneracy is therefore by no means slight. Each disease can produce grave constitutional defects in the ancestor likely to be intensified in the offspring. The greatest social dangers result from tuberculosis; the next from syphilis. Typhoid fever, scarlatina, small-pox, measles, diphtheria, whooping-cough, and all other contagions, however, may produce these constitutional defects, either through the mother during pregnancy or through their secondary effects on the ancestor’s constitution. If the subject be attacked before the close of the periods of dental stress an arrest of development of the bones of the face may result with irregularities in the shape and position of the teeth. These, then, are stigmata of degeneracy, especially due, in the individual presenting them, to the contagions and infections rather than to inheritance alone.
CHAPTER VIII
Climate, Soil, and Food
Among the factors constituting environment few have impressed the biologist so much as climate, soil, and food. The seeming modifications produced by these have made a very decided impression on the sceptical Weismann, who stated that “the possibility is not to be rejected that influences continued for a long time, that is, for generations, such as temperature, climate, kind of nourishment, &c., which may affect the germ plasm, as well as any other part of the organism, may produce a change in the constitution of the germ plasm. But such influences would not then produce individual variations, but would necessarily modify, in the same way, all the individuals of a species living in a certain district. It is possible, though it cannot be proved, that many climatic varieties have arisen in this manner. Possibly other phenomena of variation must be referred to a variation in the structure of the germ plasm produced directly by external influences.”