i8o The Field Naturalisfs Quarterly Aug. 



locality {i.e., the temperature) and the character of the par- 

 ticular season. In a summer (?) like the present we may 

 well pardon the ring snakes if they seem unable to decide 

 whether it is worth while to deposit any eggs or not, and at 

 the date of writing (July 14), as far as my reports from 

 different districts go, practically no eggs have as yet been 

 deposited, though it is past the usual time. These climatic 

 changes must have a very far-reaching effect on the prospects 

 of the young reptiles, a point we may refer to in the autumn. 

 But if all goes well, the young ring snakes arrive in con- 

 siderable numbers about the end of August or early in 

 September, measuring from 6 to 8 inches long at birth, and 

 with the bright yellow collar characteristic of their species 

 well shown. In order to facilitate egress from the egg- 

 membrane, a temporary horny tooth is developed by means 

 of which the membrane is ruptured, and, its purpose attained, 

 this structure then disappears. The average number of eggs 

 deposited by an adult female ring snake may be put at from 

 twenty-five to thirty in a season.^ 



In addition to the ring snake, the only other indigenous 

 reptile which is an egg-layer is the rare South of England 

 Sand Lizard, Lacerta agilis. This species is practically con- 

 fined to Dorset, Hants, Surrey, and other counties south of 

 the Thames. Very few authenticated specimens have been 

 taken in counties north of this, though it is constantly re- 

 corded in mistake for the common lizard. In this species 

 the egg-membrane is of much firmer consistence than is that 

 of the ring snake, the white eggs having the appearance of 

 stiff parchment and varying from five to eight, being extruded 

 in May or June and hatched about the beginning of August. 

 The young " are grey-brown above with white black-edged 

 spots — the under parts are whitish." - 



We may now turn our attention to the four British reptiles 

 which are ovo-viviparous. The first half of September is the 

 most usual date of birth of young adders, but again in this 

 species, as in all the others, the influence of the particular 

 season has to be allowed for. I expect that this year will 

 prove a very late breeding season, and if the autumn is wet 

 and cold it will go hard with the young adders. In an 



' British Serpents, p. 21. - Amphibia and Reptiles, Dr Gadow, p. 554. 



