Atwood—The Viceral Anatomy of the Garter Snake 549 
The Ovaries and Adrenal Bodies. 
The ovaries vary in position with the adrenal bodies. The 
right adrenal body lies along the vena cava but the left usually 
lies along the left efferent renal vein. In three specimens it was 
situated at the anterior end of this vein and came in contact with 
the vena cava. In specimen No. 1 the left adrenal body lay 
wholly along the vena cava a half inch anterior to the junction 
of the efferent renal veins. 
As in other snakes the ovaries are attached by the mesentery 
to the adrenal bodies and are very closely associated with them. 
The oviducts extend anterior to the ovaries and when filled with 
eggs are very large. The left oviduct is short and contains a 
smaller number of eggs than the right. The right oviduct when 
filled with eggs extends forward to the pancreas and crowds this 
organ up close to the liver. The total number of eggs in the 
right oviducts of seven large specimens was 101, in the left 
oviducts there were 51. This would indicate that the capacity 
of the right oviduct is twice that of the left, and gives an aver¬ 
age of 21.7 eggs per snake. The largest of these specimens mea¬ 
sured 34.5 inches in total length and contained 33 eggs. 
The Kidneys. 
The kidneys of Thamnophis are like those of other snakes in 
most particulars. They are very deeply lobed. The right kidney 
often extends beyond the junction of the efferent renal veins. 
When it does it sends blood into the vena cava through one or 
more small twigs. In nine specimens which varied in body 
length from 22 inches to 28 inches, averaging 23.8 inches, the 
kidneys averaged three inches in length. In the specimen of 
T. sauritus sackeni, which measured 22.5 inches in body length, 
the right kidney measured 1.4 inches, the left 1.25 inches. If the 
kidneys in this specimen were normal there is considerable dif¬ 
ference in the size of the kidneys in the two species. 
Discussion. 
The blood system of Thamnophis is very similar to that of 
Tropidonotus natrix as described by O^Donoghue (T2). This 
tends to confirm the belief that the two genera are very closely 
related. 
