TERATOLOGY. 



947 



to the placenta of the Ruminants. The 

 smallest amount of deviation is a division 

 into two coherent lobes, which are separated 

 only by a small constriction (J. F. Meckel, 

 Ebert). Such a placenta has an oblong form. 

 Sometimes there is a single lobe adjoined to 

 the placenta (placenta succenturiatd] ; it is of 

 much smaller dimensions than the placenta 

 itself, and united to it by vessels, without a 

 cord. The placenta may also be divided into 

 three (Rohault, Schwencke), four (Hoboken), 

 five (Meckel), or seven lobes (Kerckring, 

 Wrisberg). In the observation of Kerckring, 

 the arrest at a lower stage of development is 

 clearly shown by the presence of the Vena 

 omphalo-mcscnterica . 



3. The vessels of the umbilical cord are sepa- 

 rated near the placenta, and meet at a con- 

 siderable distance from it (Sandifort, Wrisberg, 

 Adolph). In one of the published cases, this 

 disposition of the vessels was the cause of 

 their rupture, which produced the child's death 

 by haemorrhage. Sometimes they were ob- 

 served to run separately from the placenta to 



Fig. 597. 



the abdomen of the foetus, into which they 

 penetrated through separate openings. In 

 most cases they meet each other just at the 

 umbilicus (Gavel, Van Solingen). 



4. The umbilical cord too long. The com- 

 mon length of the cord is twenty inches 

 (Roederer, Wrisberg), but it may be forty- 

 eight inches (Wrisberg), sometimes even five 

 feet (Morlanne). The usual effect of such an 

 abnormal length of the cord is a circumvolu- 

 tion of it round the body of the foetus. An 

 example of it is given in a very misformed 

 foetus in Jig. 597. 



A circumvolution of this kind may some- 

 times become dangerous : 1. By acting as a 

 ligature round the neck, and producing stran- 

 gulation of the foetus (Buchanan, Hebenstreit) ; 



2. By constricting one of the extremities, 

 and producing the spontaneous amputation of 

 Montgomery (Art. FCETUS,^. 157. Vol. II.) 



3. By forming single or compound knots. 

 Although these are in general not dangerous, 

 while the vessels are sufficiently protected 

 against pressure by the Whartonian gelatine, 

 they may nevertheless in some cases be drawn 

 so tight as to obstruct the communication 

 between mother and child (Sandifort, Irvets, 

 D. W. H. Busch) ; and sometimes the um- 

 bilical cord breaks off near the knot when the 

 vessels have become obliterated by the pres- 

 sure. Fig. 598. gives an example of this in 

 an acephalus. 



Fig. 598. 



Malformed Foetus, showing the cord entwined around 

 tiic neck and part of the boihj. 



{After Bonn.) 



5. The umbilical cord too short. Wrisberg 

 gives as a minimum a measure of seven inches. 

 It may, however, be much less. This short- 

 ness of the cord is in general accompanied by 

 a deformity of the foetus, usually by ectopia 

 of the abdominal viscera, by which it indi- 

 dicates an arrest of developement at an earlier 

 period of embryogenesis. In this way we 

 should interpret the accounts of absence of 

 the umbilical cord. 



6. Absence of one of the umbilical arteries, 

 is even observed in double monsters, but 

 occurs principally in ectopia viscerum abdomi- 



3 P 2" 



