12 PROFESSOE THOMAS DWIGHT. 



This condition is duly inverted with inversion of the viscera ; 

 but there is no record of the converse disposition, either with 

 the viscera normal or transposed. 



A not uncommon anomaly is the persistence of what is 

 commonly called the lower part of each cardinal as high or 

 higher than the renal veins, which may open each into its own 

 iliac, or the union of all in the cava inferior may occur at about 

 the same place. Now this condition may occur in cases of 

 absence of the inferior cava. Thus in all the above groups in 

 which the veins of two sides unite, i.e., in all but the first, we 

 may make a further subdivision into those in which the iliac 

 veins unite at about the usual place, and into those in which 

 they join at about the level of the renal veins. In these cases 

 of high union there is often a dilatation, or a plexiform arrange- 

 ment at the point of junction. A similar enlargement is some- 

 times seen at the level of the renals, though the iliacs have 

 united at the usual place. All observed cases can, I believe, 

 be fitted into some of the following groups. 



I. Persistence of both cardinal veins throughout. 

 IT. Persistence of right cardinal vein, the iliacs uniting at 

 the usual place. 



IIa. The same transposed in situs inversus. 



III, Persistence of the right cardinal vein with high union 

 of the iliacs. 



IIIa. The same transposed in situs inversus. 



IV. Persistence of the left cardinal vein, the iliacs uniting 

 at about the usual place. 



IVa. Persistence of the right cardinal vein in situs inversus. 

 V. Persistence of the lower part of the left and the upper 

 part of the right posterior cardinal with tlie iliacs uniting at 

 about the usual place. 



Va. Tlie same transposed in situs inversus. 

 VI. Persistence of the lower part of the left and the upper 

 part of the right posterior cardinal, with high union of the iliac 

 veins. 



The best synopsis of the literature is that by Krause in the 

 third volume of Henle's Anatomy, but it is now antiquated. 

 Good lists are given both by Kollmann and by Ilochstetter ; but 



