84 BRITISH SERPENTS. 



Food. — The dietary usually given consists of mice, 

 lizards (especially slow- worms), small birds and their 

 eggs, insects, moles, and ant-eggs. To this list I would 

 add the smooth newt, water-voles, and young rats, as 

 having come under my own notice. In the Monnow 

 Valley the staple articles of diet are mice, slow-worms, 

 and, on the banks of the Monnow river, water-voles. 



One of the parts of our snake literature which seems 



Fig. 16.— Slow- worms. 



especially defective is this question of their food- 

 supply and its digestion; and particularly difficult is 

 it to get authority for the statements which are made. 

 There are only two methods of investigation that are 

 of any real value — namely, the actual watching of the 

 reptile feeding out of doors ; and secondly, the dis- 

 section of the stomachs of adders freshly killed. The 

 former method is almost impossible, as no adder will 

 allow itself to be watched when feeding ; so reliance 



