40. THAMNOPHIS 791 
fetal membrane. After lying quietly for a few seconds, 
the young snake struggles, thrusts its head through the mem- 
brane, yawns once or twice, thrusts out its tongue, and crawls 
off, becoming at once very lively. As soon as the body 
becomes dry, the skin is shed, exuviation often beginning 
within 15 minutes after the young snake has been ushered 
into the world. Occasionally the young snake is unsuc- 
cessful in rupturing the sac, and smothers. (Ruthven.) 
These snakes are sometimes found in dry fields, but 
seldom far from water. One usually encounters them along 
the edges of streams, ponds or lakes, or in moist meadows. 
Many are so aquatic as really to deserve the name “water- 
snake.” They frequently swim on or under the surface 
of rivers and ponds, and at Buena Vista Lake I have seen 
them in patches of tules a considerable distance from shore. 
Their food consists largely of fishes, tadpoles, frogs and 
toads. Occasionally insects, salamanders, worms, fledgling 
birds (blackbirds), and very rarely small mammals and 
snakes are eaten. A specimen of 7. ordinoides couchii had 
caught a six inch trout. 
Individual snakes, especially in spring, sometimes are 
quite aggressive. On one occasion, while I was crossing a 
small grassy pasture, three or four large Thamnophis sir- 
talis infernalis came toward me hissing and striking wildly 
in the air. Their fierce attitude and combined attack evi- 
dently were intended to frighten me away, but I was unable 
to discover the cause of their excitement. On another trip 
I shot a Thamnophis ordinoides couchii in a patch of tules 
in Buena Vista Lake. This snake was nearly five feet in 
length and the shot merely stunned it long enough for me 
to grab the snake by the tail. It instantly recovered, tried 
to pull away into the tules, and, finding that it could not 
escape, turned upon me, and, with open mouth and many 
hisses, came right into the boat. Although I knew, of 
