948 



TERATOLOGY. 



nalium, and in defective formation of the infe- 

 rior part of the body. Serres hence derived the 

 conclusion, that this malformation is the con- 

 sequence of the want of one of the umbi- 

 lical arteries ; which is however wrong, as the 

 evolution of the whole body may be complete, 

 even when one of the umbilical arteries is 

 wanting. Fig. ,599. represents a specimen of 

 this kind. 



Fig. 599. 



a, aorta ; b, b, spermatic arteries ; c, superior mesen- 

 teric \dfdf common iliacs ; e, the single umbilical 

 artery ; f, vena cava. 



Mende even observed in a very well formed 

 child absence of one of the umbilical arteries, 

 together with an unusual course of the umbi- 

 lical vein, which, instead of communicating 

 with the vena portae, opened immediately into 

 the right auricle of the heart. 



7. Increased number of the vessels of the 

 cord. A double umbilical vein is constantly 

 to be found in the Quadrumana of the New 

 World (Rudolph!). In Man the unusual 

 plurality of the umbilical vessels is but ap- 

 parent, as it is produced by the persistence of 

 the vasa omphalo-mesenterica. 



8. Persistence of the umbilical vesicle, is a 

 natural condition in the Ouistiti (Rudolphi), 

 and occurs as a deviation in Man. Sometimes 

 it is only its duct that remains united with 

 the small intestine, forming what we call a 

 diverticulum. 



9. Constriction of the umbilical cord occurs 

 at the point where the cord penetrates into 

 the abdomen. In the constricted part the 

 vessels, although remarkably narrowed, still 

 allow in some measure the circulation of the 

 blood. The cord is thereby contorted into a 

 spiral. The death of the foetus is its usual 

 effect (Landsberger). Fig. 147. of the second 

 volume of this Cyclopaedia gives a represent- 

 ation of this constriction of the umbilical 

 cord. 



10. The umbilical cord too thick. Its dia- 

 meter varies from 1* Scinches. This is, 

 in general, the consequence of an uncommon 

 accumulation of the Whartonian gelatine, or 

 of an cedematous conditon. In one of the 



recorded cases, the superior extremities were 

 wanting, and the anus was closed. In other 

 cases it is occasioned by an enormous quan- 

 tity of the liquor amnii, which is usually 

 accompanied with an abnormal developement 

 or impeded growth of the foetus. 



MALFORMATIONS OF THE FOZTUS. 



It is impossible to give in a concise article, 

 such as is suited to a cyclopaedia, a complete 

 description of all the various malformations of 

 the foetus. I must refer to my manual, 

 published in Dutch, under the title De mens- 

 chelyke Vrucht beschouwd in hare rcgelmatige 

 en onregelmatige ontwikkeling, Amsterdam, 

 1840 en 1842, and to my Tabula ad i/lustran- 

 dam Embryo -genesin Hominis et Mammalium, 

 where a more full and accurate description 

 of the various kinds of malformations of the 

 foetus is to be found. I can give here only a 

 short description of the principal groups, as 

 an introduction to the doctrine of the malfor- 

 mations of the foetus. 



A. MONSTROSITIES PRODUCED BY AN 

 ARREST OF DEVELOPEMENT. 



I. Non-closure of the anterior Part of the 

 Body. 



Embryogenesis teaches us, that the tho- 

 racic arid abdominal cavities are originally 

 open, and close themselves by degrees at a 

 later period of uterine life. The late ossifica- 

 tion of the sternum and of the pubic bones is 

 the result of this original disposition. The 

 points of ossification are not formed in the 

 broad cartilaginous basis of the sternum be- 

 fore the fourth or fifth month of pregnancy ; 

 they are in the beginning widely separated 

 from each other by broad intervals in the 

 middle, and approach later to fuse into one 

 central osseous piece. This mode of formation 

 explains some of the original malformations 

 of the sternum; namely, its abnormal breadth, 

 the openings which are found in it, and its 

 separation into two parts. These two last 

 conditions denote, that the sternum is the 

 compound of two lateral halves fused together 

 (Rathke). The separation of the sternum 

 into two parts usually accompanies ectopia of 

 the thoracic and abdominal viscera. 



Sometimes, although the thoracic viscera 

 are enclosed in their cavity, the original divi- 

 sion of the sternum remains, and is covered 

 up by the skin (Ficker, Serres, Winslow). In 

 some rare cases, the whole or the largest part 

 of the sternum is absent in individuals with no 

 other deformity (Von Ammon). In most of 

 these cases the manubrium alone is present 

 (Wiedemann). In some, but very rare, cases 

 the anterior wall of the thoracic and abdomi- 

 nal cavity is only closed by the skin, and its 

 osseous and fleshy parts are completely defi- 

 cient (R. G. Mayne). The linea alba is, as 

 well as the sternum, the cicatrix of a cleft 

 existing at an earlier period. This explains 

 its abnormal breadth, obvious in those cases 

 in which the wall of the abdomen has been 



