The Ethics of Medical Homicide and Mutilation

by Austin O'Malley

In twins from two distinct ova there is no difficulty in seeing that the souls are placed in these in the same manner as the soul is put in the normal single embryo. When the twins come from one ovum the condition is not so simple. The oval nucleus is the essential part that goes from the maternal side, and human ova at times contain two nuclei, as occasionally hens' eggs do; a double-yoked hen's egg has two nuclei, and two nuclei have been found in a single yolk. Kölliker, Stöckel, and von Franque have observed double germinal vesicles in single human ova. In such a condition two spermatozoa could fecundate the two nuclei and the development go on as in the case of twins from distinct ova.

There is a theory which holds that homologous twins (uni-oval) can develop from a single germinal vesicle which splits into two primitive streaks and two gastrulas. According to this opinion, if the germinal vesicle divide entirely, two fetuses develop which are always of the same sex, and which resemble each other so closely in appearance that it is very difficult to differentiate them. This theory holds also that should the germinal vesicle not split fully, the lack of fission causes the various kinds of double monsters. The germinal vesicle that supposedly splits into two is not fecundated by two spermatozoa, they say, because where there is only one nucleus in the beginning, the entrance of a second spermatozoön commonly kills the ovum. This last assertion has been disproved of late.

Some followers of the splitting theory hold that double monsters arise from the union of two originally separate primitive traces (Verwachsungstheorie). Others say that a single primitive trace of blastoderm cleaves more or less thoroughly and makes the double monster (Spaltungstheorie). The earliest human double monster (Ahlfeld's case) was in the fourth week of gestation; therefore whatever is held in these theories as regards human monsters is only through analogy with lower animals.

Gerlach[57] saw bifurcation at the cephalic end of a chicken embryo sixteen hours old. In this case the first change was a broadening of the anterior end of the primitive streak; next a forked divergence appeared, and by the twenty-sixth hour the bifurcation was half as long as the undivided posterior part. Whether this was a case of two nuclei or not is not known.

What seems to make for the fission theory is that in non-parasitic double terata, no matter how unequally nourished or how variable in extent, the union between the halves of double monsters is symmetric, and the same part of each twin is joined. This fact is used as a reason to exclude a fortuitous growing together of dissimilar areas of cell-masses, at least in non-parasitic cases. Born,[58a] in a study of fish ova, found that eggs which produce double monsters begin with a segmentation like that of the simple normal ovum. Composite spermatozoa have been observed with two and three heads and one body and tail-piece, but the significance of these abnormal cells is not known.

Embryos of sea-urchins in the two-cell and four-cell stages can be separated by shaking into isolated blastomeres, and the segments will grow into full though dwarfed larvae. The same division with the growth of dwarfed larvae has been made in Amphioxus, in the teleost Fundulus, in Triton, in a number of Hydromedusae and several other low forms of life. When the division is not made completely double monsters result.

Up to a certain stage of development the blastomeres of the Medusa embryo are totipotent, or capable of developing into any part of the body. The limitation of development in a particular case lies in the cytoplasm rather than in the nuclei of the cells. If frogs' eggs are fastened in abnormal positions, inverted or on the side, a rearrangement of the egg material results, wherein the nucleus and cytoplasm rise and the deutoplasm sinks. This change of axis shifts the embryo. If an egg is turned upside down in the two-cell stage, a whole embryo, or half a double embryo, may arise from each of the two blastomeres, instead of a normal half-embryo. A half-embryo or a whole dwarf may arise according to the artificial position of the blastomere. Each of the two blastomeres contains all the materials potentially for the formation of the whole body, and these materials build up a whole body or a half body according to the grouping they take on. Primarily the egg cytoplasm, in low forms of animal life, is totipotent; it has no fixed relation with the parts to which it gives rise, and may be artificially modified or differentiated. These effects, from position and traumatic dislocation, suggest explanations for teratic forms in higher animals.

Human terata are now commonly classified in four groups: (1) Hemiteratic; (2) Heterotaxic; (3) Hermaphroditic; and (4) Monstrous. Hemiterata are giants, dwarfs, persons showing anomalies in shape, color, closure of embryonal clefts, in absence or excess of digits, or like defects. The Heterotaxic group are persons whose left or right organs are reversed in position. A true Hermaphrodite would have the complete reproductive organs of both sexes, but such an individual has not been observed. There is never any question of double personality in hermaphrodites.

Terata more properly so called may be single, double, or triple; and single monsters may be autositic or independent of another fetus, or they may be omphalositic, dependent upon another which is commonly well developed and which supplies blood for both through the umbilical vessels. There are four genera of autositic single monsters, with eight species and thirty-four varieties. Of the monstra per defectum the commonest are caused by a failure of closure in the embryonal medullary canal, which leaves part of the brain and spinal cord or their bony covering lacking. Some terata, as the Acephalia, have no brain or spinal cord, but they die in the fetal stage. The Anencephalia may have a spinal cord, a medulla oblongata, and parts of the basal ganglia, but the cerebral hemispheres are wanting. Such monsters are sometimes born at term and live for several days: they cry, suckle, show some reflexes and a sense of pain, and move the arms and legs.

I described the various kinds of terata in Essays in Pastoral medicine,[58b] and of these the most important in the matter under discussion here are the double and triple monsters. Many of the double monsters evidently were two persons. There is only one well authenticated case of a triple human monster, and this happened in Italy in 1831. It had a single broad body with three distinct heads and two necks, and was killed in delivery. There is no proof as to whether it was one or more persons. The standard of judgment in such cases as regards the presence of one or two souls in the monster is the evidence of one or more distinct consciousnesses. A monster double from the navel or breast downward (terata anadidyma) is, I think, one person. There was an example of a monster in this group which was divided from the foreheads downward; or better, the distinct twins were united by their foreheads only; but such a form is very exceptional. In my article on "Human Terata and the Sacraments," in Essays in Pastoral Medicine, in 1906, I expressed the opinion that a monster which is single to the navel and double below is composed of two persons, but I now am of the opinion that such a monster is only one person, because there is apparently only one consciousness. There are about eight cases of two-headed monsters known which were evidently two persons in each case, and several terata kata-anadidyma, divided above and below but joined at the sternum, abdomen or sacrum. Several ischiopagic twins, joined at the pelvis with the heads at the opposite ends of the double body, are grouped with either the katadidyma or kata-anadidyma. It is commonly not difficult to recognize individuality or duality of personality in monsters, but it is not easy to explain the origin of life, to point out the moment the second soul enters these fused or undivided twins.