268 The Field Naturalisfs Quarterly Nov. 



opposed to the dark -bluish or black belly of the male. 

 Next, occupying the lower half of the illustration, the mouse 

 is seen within the gullet, the head appearing through the 

 incision in the gullet. The two fore -limbs of the field- 

 mouse can be distinctly made out through the tightly 

 stretched gullet, and farther back — i.e., towards the head 

 of the adder— the hind-limbs and tail of the rodent appear 

 through the other incision in the gullet. Careful observa- 

 tion will also reveal the teeth of the mouse, the mouth being 

 open. At the lowest point of the photograph the gullet 

 narrows, and opens into the small stomach, or, as it is 

 more accurately called, the mid -gut. The walls of this 

 organ are much thicker than those of the gullet, as can 

 be seen, and as a matter of fact the mass of food does not 

 enter this portion as a whole, but is digested as it passes in, 

 a point I have repeatedly observed. The position of the 

 field-mouse is the usual one : almost invariably these small 

 rodents are swallowed head first — indeed I do not remember 

 seeing a case in which the reverse obtained. Note, lastly, 

 how the gullet at once is constricted over the tail of the 

 mouse, showing its great elasticity. The general colour of 

 this mouse is a light reddish-grey above and nearly white 

 beneath, the hind-feet being long and white. These white 

 characters can also be seen in the illustration. 



The total length of this long-tailed field-mouse {Mus 

 sylvaticus) Mr Forrest gives as about 8 inches (' Fauna of 

 Shropshire,' p. 72), which closely corresponds with the 

 dimensions of this particular specimen. 



I need not point out the bearing of this adder and the 

 contents of her gullet on the swallowing theory : it only 

 proves the possibility of it from one point of view — viz., 

 that of the capacity of the gullet to hold an average-sized 

 family of young adders. Any one who has seen the small 

 space occupied by the young in the egg-membrane just 

 before birth, and the remarkable coil in which they are 

 then disposed, will recognise that here is a case demanding 

 an equal if not greater holding capacity on the part of the 

 gullet. That, however, is only one of the difficulties of the 

 question, and in no way affects the probabilities of the 

 phenomenon, or the value of other evidence. 



