I04 The Field Naturalist' s Quarterly May 



the central and northern parts of England, as well as in 

 Scotland and Wales, the usual time of their reappearance 

 is towards the end of March or early in April. 



Secondly, The different species are variously affected by 

 temperature. The adder stands cold better than the harm- 

 less ring snake, consequently is encountered astir a little 

 earlier in the spring. In the same way I am inclined to 

 think, from my own observation, that the slow-worm be- 

 comes active rather before the common lizard ; but I 

 should not like to be too dogmatic on this point, as the 

 little Lacerta vivipara is very apt to escape observation as 

 compared with the more prominent Anguis fragilis. 



Thirdly, The character of the particular season has of 

 course a determining influence on the date of the appear- 

 ing of the reptiles. In a cold damp spring it may be as late 

 as May before any are observed. Such a spring was that of 

 last year (igoi), when in Herefordshire the first adder I saw 

 was on May i6, quite a month later than usual. This year 

 I obtained my first spring adder on March lo, and another 

 four days later, both of them being males, a point to be 

 referred to again. 



There is a fourth consideration which I have observed to 

 apply to adders, and that is, that the period of hibernation 

 is longer in old adders than in young ones. In other words, 

 the reptile-collector will find that the majority of the first 

 few adders taken in early spring will consist of the young 

 males. 



The question of sex seems to play an important part in 

 the movements of reptiles in spring. If a collection of 

 adders were made with specimens taken solely in the 

 spring months, the males would be found to preponderate 

 very largely. In fact, it is quite exceptional to take a 

 female adder early in spring. A little later, in June, both 

 sexes are taken in about equal numbers and frequently 

 together ; whilst in the autumn months the females are 

 much more in evidence than the males. Thus a collec- 

 tion, to be representative of the true proportion of the 

 sexes in any given locality, must be the result of work 

 from early spring to late autumn, otherwise misleading 

 conclusions will be arrived at. *" 



