24 THE AMERICAN NATURALIST. 
ago which would drink water out of a small graduated glass 
while I held it in my fingers. This snake learned to know 
very well that when I opened its cage door something in the 
line of food or drink was forthcoming. Several other copper- 
heads that I kept at different times became quickly tame, and I 
found them easily satisfied with pieces of fish, which they pre- 
ferred to beef. Water-moccasins became very tame also, but 
they are much more sluggish, and therefore less interesting. 
Of the latter I kept one pair nearly seven years in the cage. 
I suppose I would have them still if some one had not killed 
them by throwing boiling water on them when I was taken ill. 
The greatest enemy of snakes kept in captivity I found to 
be a flat worm, shaped and colored almost like a leech, which 
penetrates all tissues. I found them at one time in the peri- 
cardium of a rattlesnake. Once these parasites manifest them- 
selves, it is generally the death warrant to all snakes kept in 
confinement at the time. Another very troublesome and 
usually fatal affection appears in the shape of brownish-looking 
pustules; they are malignant, and the only chance in keeping 
the other snakes is isolation of the affected ones. I have seen 
a few recover by rupturing the pustules and sprinkling aristol 
on them. 
In conclusion I may add that some weeks ago I received 
seven specimens of Crotalus atrox from San Antonio, Texas. 
Six of them are full grown; the other one is a small one of 
about eighteen inches in length, which is feeding lustily on 
Anolis. The venom of this little snake is evidently of consid- 
erable strength, for the death of the lizard ensues almost instan- 
taneously after the bite. Three of the other six are evidently 
males. Sexual congress took place between one pair on May 
_ 14. The males are a little smaller and darker than the females. 
All are very excitable at present, any noise about the room 
being sufficient to start them to rattle. There seems to be 
absolutely no limit to their rattling. So far all of them have 
refused food. A young rat, which I put into the box, I had 
to remove again after two days, for the snakes never attempted 
to kill it. 
