These four kinds of omphalosites are either dead when born, or they die as soon as the placental circulation is cut off. If there is any probability of life, the physician should give them baptism before the placental circulation is stopped.
Nothing satisfactory is known concerning the etiology of single monsters. Landau, and other authorities as great as he is, reject the theory that maternal impressions from fright or exposure to the sight of hideous deformity are the cause of terata. I think the father is accountable for terata as often as the mother is. Barnes, an English physician, and others claim they find that terata are frequent in consanguineous marriages, but I have not been able to verify the a.s.sertion.
It seems a theory may be offered to explain the single terata. In 1888 Roux of Breslau by puncturing one blastomere of a frog"s egg in the two-cell stage killed the punctured blastomere without affecting the other. The punctured blastomere remained inactive, but the other developed into a complete _half_ embryo.
Crampton by separating and isolating the blastomeres in the two-cell stage obtained a half embryo; and Zoja by isolating blastomeres of the medusae, Clytia and Laodice, got _dwarfed_ larvae.
Wilson succeeded by the separation through shaking of the blastomeres in the two-cell and four-cell stages in developing Amphioxus larvae, which were half the natural size for the two-cell blastomeres, and commonly half the normal size from the four-cell blastomeres, yet in the latter some of the larvae were of the normal size but imperfect From the eight-cell stage he got only _imperfect_.
larvae. Similar results were obtained by other operators with various eggs.
Driesch and Morgan by removing part of the cytoplasm from a fertilized egg of the ctenoph.o.r.e, Beroe, produced imperfect larvae showing certain defects which represent the parts removed.
In these cases of injured and isolated blastomeres we have, it seems to me, a plausible theory for the etiology of single terata. The blastomeres in the human ovum may perhaps be injured in part by toxins from the mother, or they may be defective through disease in the ovum or the spermatozoon. They also may possibly be displaced traumatically, but this seems to be doubtful.
There are three theories concerning the origin of omphalositic {77} terata. Ahlfeld (_Missbildungen des Menschen_, Leipsic, 1882) holds that the autosite is stronger than the omphalosite, and as a consequence the foetal circulation in the omphalosite is reversed, and development is thus checked. Dareste (_Production artificielle des monstruosites_, Paris, 1876), Panum (_Beitrag zur Kenntniss der physiol. Bedeut. der angeboren Missbildungen, Virchow"s Archiv.,_ 1878), Perls (_Lehrbuch der allgem. Pathologie_) and Breus (_Wiener med. Jahrbuch_, 1882) maintain there is an inherent original defect in the omphalositic child which prevents development of the blood-vessels, and that Ahlfeld"s theory of an indirect umbilical connection of the omphalosite to the placenta is not probable; if it were, omphalosites would be very common, because one of twins is nearly always stronger than the other. Hirst and Piersol (_op. cit_) combine these theories. This kind of monster is certainly an imperfectly developed human individual, and even the Foetus Anideus should receive at the least conditional baptism.
The next group comprises the composite monsters. Normal twins may arise from the fertilisation of one ovum and of two distinct ova. In 506 cases examined by Ahlfeld he found that 66 twin births came from single ova. Twins from a single ovum are always of the same s.e.x, and they are not easily distinguished one from the other. Triplets may arise from one, two, or three ova. The elder Saint-Hilaire thought that composite monsters arise from the fusion of two impregnated ova, but this opinion is now generally rejected. Composite terata in every instance arise from a single ovum.
There is a divergence of opinion, however, as to the origin of a composite monster in the single ovum. Some authorities maintain that these monsters arise from the union of two originally separate primitive traces. This supposes primitive duality followed by fusion (_Verwachsungstheorie_). Other writers hold that there is originally one primitive trace, and that composite terata are the product of a more or less extensive cleavage of this single blastoderm. This supposes primitive unity followed by fission (_Spaltungstheorie_).
Here, as in the case of normal development, the argument is founded on a.n.a.logy. The earliest stage in the development of a human double monster observed was at the fourth week after fertilisation--Ahlfeld"s case.
B. Schultze (_U. anomale Duplicitat der Axenorgane, Virchow"s Archiv._) and Panum and Dareste (_op. cit._) hold the fusion theory-- {78} the fusion of two separate blastoderms in one ovum.
Panum and Dareste have seen two separate normal blastoderms on one ovum. Allen Thompson in 1844 (_London and Edinburgh Monthly Journal of Medical Science_), Wolff, von Baer, and Reichert also observed two embryos in one ovum. Dareste is of the opinion that the fusion of two separate ova is impossible. The fission theory--the fission of a single blastoderm to make a composite monster--is supported by Wolff, J. F. Meckel, von Baer, J. Muller, Valentine, Bischoff, and others, especially by Ahlfeld. Ahlfeld says that this single blastoderm is split by pressure.
Gerlach also (_Die Entstehungsweise der Doppelmissbildungen, etc.,_ Stuttgart, 1882) admits fission, but he contends that it is not so simple a process as Ahlfeld thinks it is. It is not a pa.s.sive cleavage, but a result of a force in the cell-ma.s.s existing before differentiation. Gerlach calls fission at the anterior or head-end of the single blastoderm, _bifurcation_; and he has actually observed such bifurcation in a chick embryo of sixteen hours (_U. d.
Entstehungsweise der vorderen Verdoppelung. Deutsche Archiv. f.
klin, Med.,_ 1887). In this case the first change noticed was a broadening of the anterior end of the primitive streak; next a forked divergence appeared, and this became more p.r.o.nounced; until by the twenty-sixth hour the bifurcation was half as long as the undivided posterior part. From each anterior end of the diverging branches a distinct head-process extended. Allen Thompson (_loc.
cit._) in 1844 saw a goose-egg, which had been incubated for five days, in which was a double monster divided to the neck.
Beyond this observation by Gerlach we have the fact, which seems to make for the fission theory, that no matter how unequally nourished or how variable in extent, the union between the halves of double monsters is always symmetric--exactly the same parts of each twin are joined. This seems to exclude a fortuitous growing together of dissimilar areas or cell-ma.s.ses, for non-parasitic double terata at the least. Born ( _U. d. Furchung des Eies bei Doppelbildungen, Breslauer Aerztl. Zeitschr._, 1887), in a study of fish ova, found that ova which produce double monsters begin with a segmentation like that of the single normal ovum.
If fission is complete h.o.m.ogeneous twins are the result; these twins are of the same s.e.x and very similar in appearance. Incomplete fission, as has been said, gives rise to double or triple terata. If one of the teratic twin embryos is stronger than the other, the various combinations of enclosure and parasitism may result, although the origin of parasitic double terata is not convincingly clear. A triple {79} monster, according to the fission theory, arises from a double incomplete cleavage of the primitive trace. Dr.
Ephraim Cutter has observed teratic composite spermatozoa which, he thinks, probably have influence in producing composite monsters.
There are three orders of the double autositic monsters: _Terata Katadidyma,_ in which the embryonal fission was at the cerebral end; the _Terata Anadidyma_, divided below; the _Terata Anakatadidyma_, divided above and below, but joined at the middle of the body. There are four genera of the Terata Katadidyma with many species. The first genus is the _Diprosopus,_ the double-faced. The doubling varies from the finding of two complete faces to a slight trace of duplex formation in one head. Forster in 500 human monsters observed 29 cases of diprosopi.
There are six species of diprosopi: 1. _D. Diophthalmus,_ which has only two eyes, but there is a doubling of the nose. 2. _D. Distomus_, which has two mouths, two lower jaws, two tongues, one pharynx, and one oesophagus. 3. _D. Triophthalmus_, which has three eyes, and the doubling of the face is more complete. There are only two ears. 4. _D.
Tetrophthalmus_, which has four eyes and two well-separated faces. 5.
_D. Triotus_ is like the last, but it has three ears. 6. _D. Tetrotus_ has four ears, four eyes, and there is some doubling at the pharynx.
Two oesophaguses enter one stomach in this species commonly. D.
Tetrotus is rare--only one example in man is known. In all diprosopi there is only one trunk, one pair of arms, and one pair of legs. Sir James Paget had a photograph, made in 1856, of a living diprosopus, the second face of which had a mouth, nose, eye, part of an ear, and a brain (?) of its own. The two faces acted simultaneously, suckled, sneezed, yawned together.
Are diprosopi twins? An answer to this question will be clearer after a description of other composite terata.
The second genus of the Terata Katadidyma is the _Dicephalus_. This genus comprises five species, which have in each case two heads, with separate necks commonly. There are two vertebral columns, which usually are separate down to the sacrum, and they converge at the lower end. {80} In the interior organs doubling will be found corresponding to the degree of separation of the trunks. In all the species of this genus there are one umbilicus and one cord.
The first species of the Dicephalus is the _Dicephalus Dibrachius_--a two-armed, double-headed monster. In this species most of the viscera are single, but the right and left halves of each viscus are supplied by the respective foetuses, and the entrail does not become indistinguishably single until near the lower end of the ileum. There may be two ordinary kidneys and a third smaller one, two pancreatic glands, and two gall-bladders. Such a monster may be monauchenous or diauchenous.
The next species is the _Dicephalus Tribrachius Dipus_--two heads, three arms, and two legs. There is also a _Dicephalus Tribrachius Tripus_ (three arms and three legs), _D. Tetrabrachius Dipus_ (four arms and two legs), and _D. Tetrabrachius Tripus_ (four arms and three legs). In all these cases there is no doubt of the presence of twins, unless there might be some doubt as to dual personality in the Dicephalus Dibrachius. In the Dicephalus Tetrabrachius Dipus and the Dicephalus Tetrabrachius Tripus there is almost complete duplication of the internal organs, and the halves of the composite body belong evidently to individuals distinct in thought, volition, and character.
Each brain controls only its own half of the body. There are four lungs, two hearts (sometimes in one pericardium), two stomachs, two intestinal ca.n.a.ls down to the colon or lower, two livers (sometimes joined), four kidneys (or three, one of which is small), two bladders, emptied at different times through a common urethra.
Dicephali are somewhat common. Forster found 140 among 500 specimens of monsters. They are rarely born alive. The best known cases of dicephali that lived for any length of time are:
1. Peter and Paul, of Florence, born in 1316, lived thirty days.
2. The Scotch Brothers, born in 1490, lived twenty-eight years. They were at the court of James III. Above the point of union the twins were independent in sensation and action, but below the point all sensation and action were {81} common. One died before the other, and the second "succ.u.mbed to infection from putrefaction" a few days later.
3. The Wurtemberg Sisters, born in 1498.
4. The twins, Justina and Dorothea, born in 1627, lived six weeks.
5. Boy twins at Padua, born in 1691, lived to be baptised.
6. Rita-Cristina, born at Sa.s.sari in Sardinia in 1829. They lived eight months. These children had a common trunk below the breast, one pelvis, and one pair of legs. Rita was feeble and quiet, Cristina vigorous and lively. They suckled at different times; and sensation in the heads and arms was individual, but below the junction it was common. Rita died of bronchitis, and during Rita"s final illness Cristina was healthy; but when Rita died, Cristina, who was suckling at the time, suddenly expired. They had two hearts in one pericardium, the digestive tracts did not fuse until the lowest third of the ileum was reached. The livers were fused, the vertebral columns were distinct throughout. These twins were baptised separately.
7. Marie-Rose Drouin, born in Montreal in 1878. They lived seven months. Marie died of cholera infantum; and Rose then died, although she had not been directly affected by the disease. These twins were like Rita-Cristina anatomically except that they had no legs. The respirations and heart-pulsations differed, and one child slept while the other child cried.
8. The Tocci boys, born in Turin in 1877. In 1882 they were strong and healthy, and they may be living still. They resembled Rita-Cristina anatomically in every respect. Each boy had control of the leg on his own side, but not of the other leg, consequently they could not walk.
Their sensations above the juncture were distinct, and their thoughts and emotions differed.
In the Paris _L"union medicale_ there is an account of a bicephalic still-born monster, born at Alexandria in 1848, which, according to the report, had on one side a typical negro head and on the other side a typical Egyptian fellah head. This report is probably not authentic; but if it is, it would be difficult to reconcile it with the fission theory. {82} Supposing the report true, the case would have to be one (1) of superimpregnation wherein (2) a spermatozoon from each source penetrated the same ovum, (3) a bicephalic monster resulted, with (4) distinct racial characteristics. All this is extremely improbable.
Superimpregnation has happened. There are cases where negresses have given birth to twins, one of which was a negro and the other a mulatto. Instances are cited in books on Legal Medicine like those of Tidy and Beck. In Flint"s Physiology a case is recorded in which a mulatto woman in Kent County, Virginia, married to a negro, gave birth to twins, in 1867, one of which was a negro much blacker than the mother, and the other a white child, with long, light, silky hair, and a "brilliant complexion." The white child"s nose was shaped like the mother"s, but there was no other resemblance. Even supposing this to be a case of superimpregnation, that does not fully explain the extreme whiteness of one child and the extreme blackness of the other.
Superfoetation is also possible. Tidy (_Legal Medicine_) gives a case: "Mary Anne Bigaud, at thirty-seven, on April 30th, 1748, gave birth to a full-term mature boy, which survived its birth two and a half months, and to a second mature child (girl) on September 16th, 1748, which lived for one year." The second child was born four and a half months after the first, and both were "nine-months" children. It was proved after death in this case that the mother had not a double uterus, and the report is vouched for by Professor Eisenman, and by Leriche, surgeon-major of the Strasburg Military Hospital. Several other cases of superfoetation are given by Bonnar (_Edin. Med.
Journ.,_ January, 1865).
The third genus of Terata Katadidyma is the _Ischiopagus_. These twins are divided so much from above downward that the heads are at almost opposite ends of the double body. They are joined at the coccyges and sacra, and the spinal columns have nearly the same axis. The trunk organs are complete and separate, except that they are commonly fused in the pelvis. There may be two, three, or four legs, given off at right angles to the pelvis. This kind of monster is not rare. Forster collected twenty cases, and nine new examples {83} were reported in the _Index Medicus_ between 1879 and 1893. Ischiopagic twins were born in County Roscommon, Ireland, in 1827, and baptised separately. The Jones Twins, born in Typhon County, Indiana, in 1889, lived for about two years; they were ischiopagi, and they had the very unusual quality, it is said, that they differed in complexion and the colour of eyes and hair. A case was reported in _American Medicine_, September, 1903.
Cla.s.sed with the Katadidyma is the genus _Pygopagus_, although it has four legs. This form is very rare. The twins are joined only by the latero-posterior aspects of the sacra and coccyges, so that the two individuals are placed almost back to back. The trunk organs are independent, except for some fusion near the point of juncture.
Examples of this cla.s.s are the Hungarian Sisters, born at Szony in 1701, who lived to womanhood; the negresses Millie-Christine, born in 1851, and who were recently living in North Carolina; and the Blazek Sisters of Bohemia. The negresses had common sensation in the legs, but Millie could not localise what part of Christine"s legs was touched, and _vice versa_.
The second group of the double autositic monsters are _Terata Anadidyma_--terata divided from below upward. The first genus is the _Dipygus_. This has a single body above, but a double pelvis with double lower extremities in the typical cases. There is an exact description of a double monster of this kind in the Gaelic _Annals of the Four Masters_ as early as the year 727 of this era. The chronicler says in that year on Dalkey Island near Dublin, "There was a cow seen which had one head and one body as far as her shoulders, two bodies from her shoulders hindward, and two tails. She had eight legs, and she was milked three times a day."
A perfect human Dipygus with two equally developed pairs of legs is unknown. Catherine Kaufmann, who was born in 1876, and who died in 1878, had a double pelvis with double pelvic organs in part, but she had only one pair of legs. There is a similar anomaly said to be living in Philadelphia at present. Blanche Dumas, born in 1860, had a double pelvis, double pelvic organs, and three legs. Mrs. B., born in 1868, {84} had four legs--the two inner ones were smaller than the outer pair. Her spinal column was divided up to the third lumbar vertebra. Her double pelvic organs acted independently. There are living male examples of this form of monster.
The next genus is the _Syncephalus_, called also _Ja.n.u.s_ and _Janiceps_. Its lower body is double up to the umbilicus, the trunk single above that point; the head shows signs of doubling, and there are four legs and four arms; the bodies grow front to front. The head usually is large, therefore this monster is born dead.
Another genus is the _Craniopagus_--twins joined only by the skull or scalp. There are three species, named from the place of union--_Craniopagus Frontalis, C. Parietalis_, and _C. Occipitalis_.
A third group of double autositic monsters are the _Terata Anakatadidyma_, which are divided above and below, but joined from the navel to the head. There are three genera. The first, the _Prosopothoracopagus_, is joined at the upper abdomen, the chest, and the faces; the spinal columns are separate. The faces are imperfect, the jaws are united; there is a broad neck with one oesophagus, and there is one stomach and one duodenum. This is a rare form, and it can not exist out of the uterus.
A second genus, the _Thoracopagus_, has a thorax in common, and the inner legs may be united. It is, as a rule, still-born.
The next genus is the _Omphalopagus_, in which the twins are joined from the navel to the bottom of the chest. This double monster has the slightest union of all, and it is very rare. The Siamese Twins were omphalopagi. They quarrelled; one became a drunkard and the other remained temperate. They married two women, and Chang had ten children, and Eng twelve. Chang died while Eng was asleep, and the latter died two hours after he had waked and learned of his brother"s death.
There is a genus, the _Rachipagus_, the examples of which are joined behind like the cla.s.s Terata Anakatadidyma that are joined in front.
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