CANKER IN SNAKES KEPT IN CAPTIVITY. 215 
out of twenty I had from this complaint. I was then 
advised to substitute soft filtered water for the hard 
unfiltered. This I did, and for three years I have not 
lost a single specimen from this cause. From this I 
think there is reason to connect the water with the 
canker. Strange to say, the disease does not occur in 
snakes in their wild state. 
“The symptoms, taken from the examples which I 
have had in my own collection, are as follows :— 
“The mouth of the snake generally seems to get 
filled up to a greater or less extent with a kind of 
fleshy substance. The eyes frequently increase in 
size, and sometimes turn quite white and opaque, 
though this latter symptom is rather exceptional. 
Then gradually the head and neck swell up, some- 
times to such an extent that the scales become 
stretched apart. The snake in the mean time refuses 
to eat or drink. There is no outward sign of any other 
part of the snake being affected except the head and 
neck. The reptile may linger in this condition for a 
considerable time, although most of my specimens that 
were affected have died in two or three weeks. 
“The disease is highly contagious, in proof of which 
I may cite the following cases. I received a perfectly 
healthy specimen of the dice snake (7vropidonotus tes- 
sellatus), which I placed in a new vivarium which had 
only just been made, and consequently had never pre- 
viously contained snakes. The dice snake remained 
in a healthy condition for two or three weeks, when [ 
