460 
Nachdruck verboten. 
Some Vertebrate Abnormalities. 
By W. M. SMALLWwOooD. 
With 4 Figures. 
It is the purpose of this paper to report a number of abnormalities 
differing in some respects from similar ones already noted by others. 
In Fig. 1 is shown a condition of the post cava in a female cat 
unlike any that have come to my notice. This double condition of the 
post cava extends from tbe union of the common iliacs to the kidneys 
separated as in the drawing. The left 
branch is slightly larger. A curious short 
cross branch occurs just anterior to the 
union of the iliacs. A possible explana- 
tion for this anomaly might be found in 
the persistence of the posterior cardinals 
which failed to fuse in this region. The 
renals and lumbars are in their normal 
position and so far as distribution is con- 
cerned so are the spermatics. The right 
spermatic, however, is considerably larger 
than the left and is connected with the 
right lumbar. No variation was found 
in the arteries of this animal. 
The second Figure shows variations 
in each system. The spermatic arteries 
arise from different places on the dorsal aorta; while on the left 
side there are two renal veins having the renal artery passing 
between them. The supra-renal veins are decidedly asymmetrical in 
that the right empties into the right renal thereby causing a slight 
enlargement in the latter. The most interesting abnormality, however, 
is in connection with the vertebral arteries, one pair arising on the 
same side and penetrating the post cava. TREADWELL, 96, MCCLURE, 
00, 00a, and Wryssz, 03, each record instances of a single artery pene- 
trating a vein, the vein being in most instances the post cava. 
Rost Cava 
Fig. 1. 
