MONSTROSITI ES.
Monsters, as defined by Saint-Hilaiie, are deviations from the specific type, and are very complex in their nature. When they are made up of complete or incomplete elements of a single individual they are called shrill.; when they are made up of complete or incomplete elements of more than one individual they constitute composite, double or triple monsters. Saint-Hilaire has divided monsters into two classes, which we will consider in turn.
Simple Monsters.
In case of these monstrosities either there is absence of a portion of the elements of the individual, or else all the elements are present, but they are modified variously in connection and in disposition. Saint Hilaire has divided the simple monsters into three classes: The autosites; the omphalosites; the parasites.
The autosites may exist outside of the uterus, not that their anomalies in conformation are compatible with long life, but because the cessation of the placental circulation does not mean immediate death.
The omphalosites can only live in the uterus; they die as soon as the placental circulation ceases.
The parasites are of such abnormal and irregular development that they are considered to-day as being simply morbid productions, having their seat in the uterus or ovaries (moles or dermoid cysts.) Autosites.
The fcetus is composed broadly of limbs, trunk, head and face, and each of these parts may be the seat of monstrosities, which we will con sider in turn, following the classification of Saint-Hilaire.
Ectromelie Ref are characterized by the lack of develop ment of one or more of the limbs, which is supposed by Dareste to depend on anomalous development of the amnion. Cases of intra uterine amputation have frequently been confounded with these mon strosities, but there is an essential difference, as is apparent.
According as the lack of development affects one or another limb, ectromelic foetuses are divided into: the atrophy is limited to the middle segments of the limbs, the feet and the hands having continued to develop (Fig. 184); the feet or the hands, the forearms or the legs are rudimentary: the arrest in development includes all the segments to about an equal degree. (Fig. 185), Symelic monsters are characterized by the union or median fusion of two limbs of the same kind. The lower limbs may be
fused, and by their external surface instead of their internal. According as the fusion is more or less complete, these monsters are divided into: the fusion being more or less complete there 0:ism only a double foot: the union is more complete and there exists only s single foot: the fused limbs terminate in a point, the foot being lacking. According to Heckel this variety is only met with in case of female foetuses, but Saint-Hilaire has met with it in the mule.
Celosomic are characterized by a more or less complex eventration of the genitourinary organs and various viscera. The entire contents of the abdominal cavity may be found in a pouch, the walls of which are formed by the cord. There are usually present in addition anomalies of the limbs, and the sex is usually female. We distinguish, with Saint-Hilaire, cases where the monstrosity is limited to the abdomen, and cases where it extends also to the thorax. The varieties are: Aspalosomes.—Where there exists lateral or median eventration at the lower part of the abdomen, the urinary, sexual, or intestinal system opening externally by three separate orifices. The situation of these orifices is not normal. The internal genital and urinary organs are atro phied or lacking. Monsters of this variety, born alive, quickly die: Agenosomes.—Where the organs of generation and urination are lacking or rudimentary. The anus is found in front where the external genitals should be: Sellosomes.—Where there is lateral eventration at the inferior portion of the abdomen, and absence or lack of development of the pelvic limb of the same side: Schistosomes.—Lateral or median eventration throughout the entire extent of the abdomen, pelvic limbs lacking or imperfect. The abdominal wall is replaced by a thin membrane through which the viscera may be seen. This variety is very rare: Pleurosomes.—Where the fissure partially invades the thorax, and where there is atrophy or want of development of the thoracic limb of the same side as the eventration: .Kelosames.—Lateral or median eventration with fissure, atrophy or entire absence of the sternum, and hernia of the heart. The genito urinary organs are normal.