Chapter XXIV

I CONDUCTED THE PATHOLOGICAL STUDY of the twelve pairs of twins with the greatest possible care. As everyone knows, there are two kinds of twins, one-egg and two-egg. Twins born of the same egg are always identical, both in their internal and external manifestations, and of the same sex. They are variously known as identical, uniovular or monozygotic. Twins born from two separate eggs resemble one another in both their internal and external characteristics, but rather as brothers and sisters do. They are not perfectly identical and, in about half the cases, are of different sexes. They are known as fraternal, biovular or dizygotic.

These remarks constitute, medically speaking, one of the basic laws of heredity concerning twins. This law has been used extensively by those who claim that environmental factors, such as education, nutrition, the illnesses a person may have suffered, etc., influence only slightly his physical, mental and temperamental makeup, whereas heredity plays a much more important role. If the traits a person has received from his forebears occur again and again throughout several generations, they are known as dominant hereditary characteristics.

These dominant hereditary characteristics can either be to the advantage or disadvantage of the individual. For example, a good healthy set of teeth, a thick head of hair that does not thin with the years, or hypertension and, in some families, diabetes. Among the mental illnesses, nervous depression.

These hereditary phenomena, whether they are advantageous or disadvantageous, often appear at birth: a child born with too many fingers or toes would be an example. Other phenomena develop later on and become chronic illnesses, such as epilepsy, asthma, gout, certain forms of hypertension, a few cases of cancer, and the senile cataract of the ocular lens, this last occurring only in people sixty or older.

Among these hereditary phenomena one sometimes finds this peculiarity, that they occur more often in one sex than in the other. Daltonism, or congenital colorblindness, and anemia are two of the most frequent manifestations of these hereditary phenomena defined by sex. Both of these illnesses appear only in males, never in females. Anemia is the most obvious example: the most common hereditary form of anemia is that which has passed from an anemic grandfather through a healthy daughter to half the male grandchildren. Male children never inherit it directly from an anemic father. Each male child and all of his descendents will remain healthy, whether they be male or female. But the female children of an anemic father will, though in themselves healthy, carry the seeds of anemia, and each of their daughters will transmit the seeds to their male offspring.

I had the bodies of a pair of fifteen-year-old twins before me on the dissection table. I began a parallel and comparative dissection of the two bodies. Nothing particularly noteworthy about the heads. The next phase was the removal of the sternum. Here an extremely interesting phenomenon appeared: a persistent thymus, that is, a thymus gland that continued to subsist. Normally the thymus is found only in children. It extends from the upper edge of the sternum to the heart, thus covering a fairly large area. With puberty it begins to wither rapidly and soon disappears completely. Once sexual maturity has been attained, all that is left of it is a small pocket of fat, plus the remains of the fibrous tissues of the former gland.

The thymus has a great influence on growth. When it withers too rapidly, the individual will be small, perhaps even a dwarf, and besides, his tibular bones will be very fragile. Overdevelopment, or hypersecretion of the gland, is often found during the autopsy of children who have died suddenly for no apparent reason, without having been ill. Hypersecretion is also frequently found in young people who prove to be excessively vulnerable to infectious diseases.

Thus the discovery of the thymus gland in the twin brothers was of considerable interest, for not only was it still extant here in these fifteen-year-olds, whereas it should have disappeared at the age of twelve, but it was, besides, abnormally large. I dissected two other sets of twins, one of fifteen years of age and the other of sixteen, and found the thymus withered in both cases.

From each of the eight identical twins I extracted the cervical part of the spinal column. The fourth and fifth vertebrae presented an anomaly: these vertebrae had not closed up at the age of twelve or thirteen, but remained open, even in the case of the fifteen- and sixteen-year-old twins. This anomaly, called “spina bifide,” is a pathological state whose consequences can be extremely serious.

An individual develops in both directions of the spinal column, that is, upward towards the cranium and downward towards the pelvis, or rather, the caudal bone. Development is called cranial or caudal, depending on the predominant tendency. In the present case the tendency was cranial for all the twins, since the “spina bifide” and the transverse bone which had remained open were degenerate phenomena.

Another anomaly I found in the five pairs of twins was the non-fixation of the tenth rib. Normally, this rib is attached to the sternum. The fact that it was “floating” resulted from an irregularity of the spinal column’s growth in the pelvic direction.

I committed these curious observations to paper, in a much more precise and scientific manner than I have employed to describe them here, for my dissection report. Later I spent a long afternoon in deep discussion with Dr. Mengele, trying to clear up a certain number of doubtful points. In the dissection room and laboratory I was no longer a humble KZ prisoner, and I consequently defended and explained my point of view as though this were a medical conference of which I were a full-fledged member. I contradicted Dr. Mengele on several occasions, and completely disagreed with one of his hypotheses.

I know men, and it seemed to me that my firm attitude, my measured sentences, and even my silences were the qualities by which I had succeeded in making Dr. Mengele, before whom the SS themselves trembled, offer me a cigarette in the course of a particularly animated discussion, proving he forgot for a moment the circumstances of our relationship.

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