444 
NOTES TO THE 
parts-grown common mouse. It seems hardly possible that the 
mouse could ever have gone down. 
The engraving on the preceding page represents the skin of a 
viper. Directly the animal is killed, the skin or a portion of it 
should he stretched on a flat glass. The beautiful pattern of the 
scales in a skin so treated is much to be admired. Oil-cloth 
manufacturers should copy it. 
Poison Tangs or YiPER,p. 205. — Gilbert White does not seem 
to have been much of an anatomist. He probably therefore never 
dissected the poison apparatus of the viper or other venomous 
snakes. Mr. Delamotte has therefore kindly at my request 
given us drawings of dissections I have myself made of the 
poison apparatus of the rattlesnake. It is the same, on a 
larger scale, as the viper. Fig. 1 represents the palate of the 
FIG. 1.— PALATE AND POISON FANGS OF THE RATTLESNAKE. 
snake; the lower jaw is supposed to be removed altogether. The 
poison fangs, when the snake is not irritated, lie back parallel 
to the roof of the mouth, so that they will not at all interfere 
when the snake is swallowing its food. On the left hand of the 
drawing will be seen the projecting tips of the fangs. The fangs 
lie in, and are protected by a fold of the gum, which serves two 
purposes ; first of all, it prevents the poison being thrown broad- 
cast when the snake bites, and secondly, it protects the fangs 
from injury. On the right hand side are seen the fangs from 
which the bag has been dissected off with the scissors. In this 
ease there are three poison fangs all about the same size. 
Fig. 2 shows a further dissection of the fangs as contained in 
this pouch or bag. One side of the bag being cut away, it will 
