THE ADDER. 87 
has to be placed mainly on what is found in the 
stomach. The difficulty here is, that digestion is so 
rapid that the most usual thing is to find nothing at 
all. Moreover, the adder feeds at more or less long 
intervals, and the only chance is to get it just after a 
meal. Any bulky food contained in the throat or 
stomach can be easily squeezed out without opening 
the adder. Two years ago (June 1898) I captured an 
adder in a grass-field on the banks of the Monnow at 
Skenfrith (near Monmouth). TI followed it across the 
field for about 200 yards, watching its movements and 
observing its rapidity of progression, which was that 
of an ordinary walking-pace. On approaching the 
hedve I secured the adder for fear it should escape ine. 
It was very full, and when I got home I squeezed the 
contents of the gullet and stomach into a dissecting- 
dish. The first thing to appear was a young water- 
vole, qnite perfect. This was followed by a second, 
which showed signs of partial digestion. It looks as 
if the adder had paid two visits to the water-voles. In 
the illustration (p. 85) the water-vole on the left of the 
picture is seen undigested, while that on the right is 
partially absorbed. This indicates that the adder can 
retain food in the cesophagus or gullet undigested till 
it is required to be passed on into the stomach, and 
explains how it is possible for frogs and toads to have 
been rescued alive from the inside of adders, as is 
related. Though generally described as being in the 
stomach, more probably the frogs and toads were only 
