220 
Canker in Grass Snakes. 
The permanganate of potash solution barely kept the 
canker in check, the canker alternatively losing, but more 
often gaining, ground. By the end of April the sides of the 
upper jaw were much swollen due to two well-established 
canker ‘ colonies ’ between the right and left maxilla and 
their respective gums. See figure I. The mouth could not 
be properly closed and there was a gap of about one-eighth 
inch between the upper and lower jaws. In habits Rasper 
was normal, until this time. 
At the beginning of May Rasper usually held his head 
about one inch above the floor of his cage when resting, and 
continually worked his jaws as if chewing and swallowing. 
This produced the effect of blowing out his ‘ cheeks/ then 
trying to chew like a teething baby. 
By 21st May canker had rapidly gained the upper hand. 
The characteristic slime was now almost covering the 
Fig. III. LOWER JAW OF THE GRASS SNAKE (x4). 
shewing naked dentary protruding from the gum. 
s Skin. d Dentary. gGum. c Seat of Canker. 
membranes of the mouth, even the tongue sheath. Par- 
ticularly bad seats of canker were opposite the centre of the 
basisphenoid, around the anterior end of each dentary, at 
the front between the gum and maxilla at each side, and in 
three places on the gum between the teeth on the outer side 
of the right dentary. See Fig. II. 
Each day I removed the slime and thoroughly bathed the 
mouth with swabs of cotton wool soaked in a dark purple 
solution of permanganate of potash. However, the above- 
mentioned seats of canker were so deep and persistent that 
I was obliged to scrape the slime away with a fine scalpel, 
and afterwards wipe the places with tiny pieces of cotton 
wool held in fine-pointed forceps. The mouth meanwhile 
was kept open with a plug of saturated cotton wool. 
This state continued, apparently getting no better, until 
early June, when Rasper only seldom put out his forked 
tongue, and began to wince when I touched his worst 
places. 
By 20th June both dentaries were protruding, naked, 
from the gum, and beneath and all round each was a persistent 
‘ growth ’ of canker. See Fig. III. I was bitterly dis- 
appointed and grieved, and felt I was waging a losing battle 
The Naturalist 
