Bauhaus-Universität Weimar

Titel:
The Cyclopaedia of Anatomy and Physiology, vol. 4: Pla [corr.: Ple] - Wri
Person:
Todd, Robert Bentley
PURL:
https://digitalesammlungen.uni-weimar.de/viewer/image/lit29465/958/
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 ; d, d, 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 portæ, 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 (Rudolphi). 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*—2| inches. 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 Fœtus. 
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 regelmatige 
en onregelmatige ontwikkeling, Amsterdam, 
1840 en 1842, and to my Tabulce ad illustran- 
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 and 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 (Yon 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
        

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