96 ANNALS OF SCOTTISH NATURAL HISTORY 



Adder, not as a valid species, a view that does not commend 

 itself to me. But as long as serpents are classified as far 

 as external characters go by the arrangement and number 

 of their scales alone, so long must the Small Red Viper be 

 an Adder, in spite of the fact that it never attains the size of 

 an adult Adder, is always of a reddish or mahogany colour, 

 both sexes exhibiting this red tint (never seen in male 

 Adders), and has a very limited distribution. This Small 

 Red Viper is said to occur in some parts of Scotland, but I 

 have been unable to obtain any Scottish specimens of it, and 

 would be very grateful for any that field naturalists could obtain 

 in the coming spring and summer. It is said by some to be 

 merely the young female Adder, but, as I have said, both 

 sexes are found of the same size and colour. 



Another serpent that is a true variety of Adder is found 

 in Scotland perhaps more often than elsewhere, viz. the 

 Black Adder, or Coluber praester of some writers. In this 

 reptile the colour is black all over, the zig-zag markings 

 being only visible in certain lights or in preserved specimens. 

 This melanism in Adders has been carefully worked out by 

 Mr. Boulenger, who finds that it is produced differently in 

 the two sexes. In the males which, it may be remembered, 

 exhibit the blackest markings in ordinary Adders the black 

 colour is produced by a gradual extension of these markings 

 until the whole body is covered. In the females it is the 

 ground colour, not the markings, which gradually deepens in 

 tint, finally absorbing the markings in a universal black 

 body. These black Adders are extremely rare in England, 

 and any specimens taken in Scotland should be carefully 

 preserved and recorded in the " Annals." 



The local variations of the Scottish Adder in such 

 matters as size, colour, food, numbers, time of hibernation, 

 etc., afford great scope for original work on the part of field 

 naturalists a scope, indeed, hardly to be found in any other 

 natural order which is fairly accessible to observation. Such 

 problems as the following are all more or less awaiting 

 solution, and many others of a like nature. 



How do the Adders of Mull and Jura compare in the above 

 points with those of Perthshire ? Is there anything in the 

 food - supply to account for the immunity of lona from 



