72 WILD DENTISTRY. 
air-rifle. But the shot was never fired, for, 
without warning, the old rat fell over, gave 
three feeble kicks, and was still. 
When the boy picked her up he gasped. 
There was nothing of her; she was a skeleton 
—nothing more. He hurried to the chicken- 
coop she had entered, and there, to his sur- 
prise, found all the chicks alive. 
What had happened? This: The front- 
teeth of a rat grow at a terrific rate, to keep 
up with the constant wear of gnawing and 
grinding against each other. The bullet which 
had hit and displaced the lower two teeth in- 
wards had made the grinding impossible, and 
so the upper teeth had grown unchecked, 
until, forming almost a complete circle in 
front of the head, they had come up again 
to the skull, like huge tusks. 
The rat was starved to death. 
