10 PROFESSOR THOMAS DWIGHT. 



of the vertebne. It is traced below, close to the internal iliac 

 at its origin. Though a junction is probable, it is not to be 

 demonstrated. The vein is lost above in the region of the 

 kidney. The right ascending lumbar vein (figs. 1 and 3) springs 

 from the very beginning of the common iliac, to ascend in front 

 of the transverse processes, but it was lost at the lower border 

 of the 2nd lumbar. A small vein empties into the left renal 

 on the front of the spine. It forks below ; one branch being 

 lost behind the right iliac artery, the other on the front of the 

 3rd lumbar vertebra, very near the system of the ascending 

 lumbar vein. It is possible that there was a very free anasto- 

 mosis along the right of the spine, which took up the lumbar 

 veins and the lower intercostals. 



The inferior cava (figs. 1 and 3) begins at the diaphragm, and 

 runs to the right auricle. The opening through the diaphragm 

 is at its widest rather under 15 mm. The part in the pericar- 

 dium struck me, when I first saw it before injection, as very 

 unusually long. After injection, the measurements are of no 

 great value. The anterior free border is about 1 cm., and the 

 posterior somewhat over 4 cm. 



This condition would be accounted for, according to Hoch- 

 stetter's researches, as follows : The inferior cava above the 

 diaphragm is the original hepatic vein, formed by the union of 

 the vencc hepaticce revehentcs. The outshoot from this, which 

 should have extended downward a little to the right of the 

 median line, and ultimately have joined the right cardinal, pre- 

 sumably was never developed. Consequently there is no cava 

 below the diaphragm. A system of anastomoses has brought the 

 iliac veins into connection with the left posterior cardinal instead 

 of the right one. The upper part of this vein has undergone 

 the usual atrophy, the trunk being continued by the oblique anas- 

 tomosis, by which it normally connects with the right posterior 

 cardinal, the upper part of which persists as usual. How much 

 of the azygos is the original cardinal I am not prepared to dis- 

 cuss. The ascending vein opening into the right thorax is very 

 suggestive of a part of an original cardinal, but nothhig final can 

 be said on the matter. An almost precisely similar brancli is 

 seen in Gurlt's figure. The injection may have failed at this 

 point, but probably the cardinal is normally interrupted in this 



