1902 Reptile Studies 265 



The whole question of the adder-swallowing theory as it 

 stands at present is one of impartially weighing the evidence 

 for and against. If argument fails, there are those who in 

 this matter fall back on abuse, which, to say the least of it, 

 is rather unscientific. For ourselves, we have always main- 

 tained — in spite of misrepresentation in some quarters — that 

 the question remains to be proved. The balance of evidence 

 strikes us as tending to the negative, with some important 

 exceptions, which have been discussed elsewhere.^ It is 

 very difficult, however, to lightly set aside such statements 

 as that of Dr Dunstan in the ' Westminster Gazette ' 

 (October i, igoi), who must be presumed to have some 

 anatomical knowledge, and others of a similar character. 



Of the possibility of the phenomenon we have not the 

 slightest doubt, of the probability of it we have considerable 

 doubt ; but even a slight acquaintance with nature is suffi- 

 cient to teach that some improbabilities are facts, and that 

 things which at one time are regarded as impossibilities 

 may in the light of fuller knowledge come to be matters of 

 everyday occurrence. 



It may well be asked by those who have no means of 

 investigating the matter for themselves, but who carefully 

 scrutinise the evidence printed on both sides. How is one to 

 know what statements are to be absolutely rejected as unre- 

 liable, and what are worthy of consideration ? The answer 

 is, that any field naturalist who will take the trouble to 

 make himself familiar with what is known of the structure 

 and functions of the organs in the body of an animal will 

 not have much difficulty in recognising palpable errors 

 when he sees them. Also, he will be capable of recognising 

 careful observation when it presents itself. For instance, 

 many statements have been made by persons who assert 

 that they have been witnesses of the adder-swallowing, in 

 which the size of the young ones swallowed is put at about 

 3 inches.^ Fully developed embryo adders measure from 5 

 to 8 inches long ; as a rule, they are not less than 6 inches 

 long at birth, frequently 7, and not rarely 7}^ to 8. There- 

 fore a statement which gives their length at 3 inches may 

 at once be regarded as unreliable, probably the result of a 



^ British Serpents, chap. xii. ^ Ibid., chap. xiii. 



