Atwood—The Viceral Anatomy of the Garter Snake 543 
one to three veins enter the portal from the epigastric vein. 
They are usually connected with the fat body and the intestine. 
Along the liver branches from the epigastric vein enter the 
tissue of the liver to the left of the vena cava but do not enter 
this vein. These varied in number from four in No. 3 and No. 
4 to thirteen in No. 7. 
At the anterior end of the liver the portal vein is continued 
forward and receives blood from the intestine and also from the 
epigastric vein by a large branch which may be absent. 
Anterior to the heart a large vein enters the left jugular from 
the epigastric. It was present in all specimens excepting No. 4. 
In Nos. 6, 9 and 18, it occurred as two veins, and No. 11 had 
three separate veins about a half inch apart (Fig. 1). The fact 
that this vein varies greatly in the garter-snake agrees with con¬ 
ditions found to exist in Zamenis constrictor, (Atwood, T6). 
The connections of the epigastric vein in the neck region have 
been described in the discussion of the right jugular vein. 
The Respiratory System 
The right lung originates dorsal to the heart and lies in the 
right, dorsal part of the body-cavity. It extends beyond the 
caudal end of the liver nearly to the anterior adrenal body in 
the specimens from Illinois, Michigan, and Wisconsin. In the 
specimens from Florida it is longer, reaching beyond the an¬ 
terior adrenal in all cases and to the mid-kidney region in some. 
In all of the females from Illinois, Michigan and Wisconsin 
the lung was less than half the length of the body without the 
tail. In the specimens from Florida the lung was more than 
half the length of the body. In one male from Wisconsin the 
lung-length was slightly more than half the body-length. 
Although this difference in the length of the lung seems to 
be quite pronounced and constant I do not consider it of specific 
significance. It is probably correlated with a more rapid metab¬ 
olism due to higher temperature. 
The left lung is small and rounded but functional, and is con¬ 
nected with the trachea by a pore one sixteenth of an inch an¬ 
terior to the termination of the tracheal tube in the tissue of the 
right lung. It is situated to the left of the pulmonary vein. 
The alveolar tissue of the trachea begins gradually near the 
head and becomes more and more prominent until the lung is 
