Canker in Grass Snakes . 219 
swabs of cotton wool soaked in a solution of one teaspoonful 
boracic acid to one breakfast cup of warm water. 
The following day three more white flecks appeared, one 
in the same place as previously, the second near the anterior 
end of the left dentary between the bone and the gum, and 
the third in the centre of the roof of the mouth. 
Each day until 24th April I removed any canker ‘ spots 
and thoroughly bathed the mouth, inside and out, with a 
Fig. II. VENTRAL VIEW OF THE SKULL OF THE GRASS SNAKE (x4). 
(T ropidonotus natrix ) . 
d Dentary. p Palatine. m Maxilla. k Basisphenoid . 
solution of two teaspoonfuls boracic acid to one breakfast 
cup water, paying special attention to the teeth, but this 
treatment only held the disease in check. On the 24th I 
changed the mouthwash from boracic acid solution to a weak 
solution of permanganate of potash and used it once a day until 
the 28th when the snake escaped. Later in the day Rasper 
was found sunning himself on a wall in the hottest part of 
the garden, and standing nearby, staring at him with glassy 
eyes and wet hair standing on end, was a young black cat. 
Up till now Rasper had never looked or behaved as if he 
were sick. The fresh air and direct sun had made him even 
more lively than usual, and he certainly showed his disapproval 
of being taken back to his cage. 
1933 Oct. 1 
