944 



TERATOLOGY. 



the forehead, round which is twisted the um- 

 bilical cord, 



Fig. 596, 



In some, but very rare, cases, the coats of 

 the ovum are destroyed, and the foetus is im- 

 mediately attached to the inner surface of the 

 uterus (Steinmetz). It is not to be denied, that 

 through these pseudo-membranes some mal- 

 formations of the foetus may be occasioned, as 

 Montgomery has proved, such as the truncation 

 of the extremities, which he names self-ampu- 

 tation. Further than this, however, we may 

 not go, for the brides placenlaires of Professor 

 St. Hilaire are certainly not a universal cause 

 of monstrosity. They are too accidental and 

 unstable to be such. The existence of mal- 

 formations in eggs which Geoffrey St. Hilaire 

 coated over with varnish or wax, affords no 

 proof of the possibility of a mechanical origin 

 of monstrosities. The exclusion of the air pre- 

 vents, in such a case, the necessary material 

 change in the ovum, in consequence of which 

 the perfect developement of the foetus is im- 

 paired. 



The morbid state of the coats of the ovum 

 may likewise cause the so-called mote, which, 

 according to their consistency, are divided 

 into moke fungosce, carnosce, cruenta, and 

 tendinoste. Valentin* distinguishes in the san- 

 guineous mass of mola carnosa a net of vessels, 

 from which the blood issues. It is the vas- 

 cular net of the chorion, in which the mass of 

 blood has been collected, in consequence of 

 too great a supply from the uterus. By these 

 means the villi are distended and removed. 

 The ovum being thus degenerated, occasions 

 defective respiration and nutrition of the 

 foetus, which in consequence soon dies. The 

 ovum, however, may still continue to grow, 

 and is finally expelled. In this manner these 

 molae are frequently the cause of miscarriage. 



Kerckring* inveighed in a spirited and in- 

 genious manner against the strange accounts 

 which were formerly given of these molts. 



To the diseases of the placenta are referred 

 enlargement (Kyll, Pierrard, Devilliers), con- 

 gestion and apoplexy (J. Clarke, Darigan), 

 calcareous concretions (Hannover). For the 

 aetiology of malformations, this pathological 

 anatomy of the placenta is, however, very un- 

 productive. None of these can be explained 

 by it, nor were any accompanied by these pla- 

 cental diseases: 



Nor does the nosology of the foetus afford 

 us much more information, notwithstanding 

 the monograph given by J. Gmesser.-)- It 

 cannot, however, be denied, that some of its 

 diseases may give rise to deformities ; for in- 

 stance, chronic inflammation of the brain to 

 hydrops ventriculorum cercbri t and this again 

 to Acrania. 



Perhaps also, as Rokitansky states, a morbid 

 condition of the valves may be the cause of 

 some congenital abnormities of the heart. 

 Yet, notwithstanding all this, the diseases of 

 the foetus can only, in a very limited sense, 

 be assigned as the cause of its malformation ; 

 and hence the opinion of Otto, who ascribes 

 to this source a gre^t many malformations, 

 ought to be rejected. 



4. A fourth, and assuredly very general, 

 cause of malformation, consists in impeded de- 

 velopement of the foetus by some remote and un- 

 known cause. It is matter of dispute whether 

 this deforming cause operates on the foetus in 

 its totality, or whether it affects originally 

 only one system, which spreads its deforming 

 influence over all the others. This last idea 

 was embraced by Tiedemann, who at first de- 

 duced all monstrosities from some defect of the 

 vascular, and later from the nervous system. 

 In opposition to this hypothesis, I suggest the 

 following considerations. 



a. It is opposed to anatomical evidence. 

 The cyclopia, whose nature consists in a more 

 or less simplified eye and a displaced or 

 absent external nose, is attributed by Tiede- 

 mann to the original absence of olfactory 

 nerves, producing the deformation of the 

 nasal cavity, and the original fusion of the 

 optic nerves, and of the thalami nervorum 

 opticorum effecting the simplification of the 

 eye. I have found, however, in cydopes, 

 more than once, olfactory nerves, and have 

 likewise seen that there was no constant con- 

 currence between the simplified form of the 

 eye and of the optic nerve. A double optic 

 nerve may be found with a simile eye-ball 

 (Eller, Henermann). With complete dupli- 

 cation of the internal parts of the eye, and 

 even with two separate eyes, I found a single 

 optic nerve, and likewise a double, though 

 not complete, as well as a single eye-ball, 

 notwithstanding the entire absence of the 

 optic nerve. Similar facts are quoted by 

 Haller and G. F. Wolff. Hare-lip with cleft 



* Specil. Anat. Amstelodami, 1670, Observ. 38 

 " Repert. Anat u. Physiol., Berlin, 1837, B. i. et 95. 

 127 - t Di e Krankheiton des Foetus. Breslau, 1827. 8vo 



