BRITISH REPTILES 
commons, woods, hillsides, grassy and sandy banks, 
heaths, rides, quarries, etc. A chalky soil appears to be 
a favourite retreat, yet, curiously enough, we have 
rarely met with this species on our own Chalky Chilterns 
in Northern Hertfordshire. The average number of 
young is given as 13, though less and much larger figures 
have been stated. I knew of a dam Adder in Sussex 
which was accompanied by a family party of 16. The 
young are born in late Summer or early Autumn, this 
being a viviparous species. ‘The usual dietary consists 
of ant-pupz (often erroneously referred to as ant-eggs), 
birds and their eggs, insects, lizards, mice, moles, and 
slow worms. Newts, young rats, and even water-voles, 
have also been known to be taken. Adders vary a great 
deal in colour, and my old friend Professor Gerald R. 
Leighton has no hesitation in stating that they vary from 
black to white! He gives as a general description of 
the body-colours those of deep and pale blue, mottled- 
grey, orange, and yellow. The black, brown, or warmer 
colour marking on the head, and along the back, is not 
subject to such variation as the body-colourings. By 
these dark markings the Adder may at once be distin- 
guished from other Snakes on the British list, and 
especially by the curious V-shape mark on the crown of 
the head. The average length of an adult is 20 to 25 
inches. Female preponderate (it is said in the proportions 
of as many as three or four to one), but Vipera berus is 
for the most part a shy, if not nervous creature, and will 
do all that is possible to glide out of harm’s way if danger 
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