THE ZOOLOGIST 



No. 711.— September, 1900. 



THE ADDER-SWALLOWING THEORY FROM AN 

 ANATOMICAL POINT OF VIEW. 



By Gerald Leighton, M.B. 



The main objections of scientific naturalists to the belief that 

 the Adder-mother {Vipera berus) swallows her young are the fol- 

 lowing : — First, that no Adder has been dissected by a competent 

 authority with the young found in the gullet. Secondly, that the 

 cubic capacity of the gullet is not sufficient to hold all the young 

 ones in a litter. Thirdly, some (F. G. Aflalo, e.g.) hold that 

 there is no adequate reason for the phenomenon, i.e. that the 

 young ones would have a better chance of escape if they were not 

 thus swallowed. Of these objections, the second is by far the 

 most pressing to my mind, for if it could be shown that the gullet 

 of the Adder is not capacious enough to hold the average number 

 of young, then indeed one could not have much belief in the 

 occurrence. It is this point that I wish to deal with at present. 

 One must settle — 



1st. What is the average number of young at a birth ? 



2nd. Is the anatomical structure of the gullet adapted for the 

 reception of young ? 



3rd. Is the capacity of the gullet sufficient ? 



These are practical questions, only capable of decision by 

 dissection of a sufficient number of adult female Adders. Take 

 them seriatim. 



Zool. 4th ser. vol. IV., September, 1900. 2 e 



