THE YOUNG NATURALIST. 



125 



Mr. Buckland : — " I took the greatest care of my new pet and it was lucky 

 I did so. In a few days it was discovered that my new snake had increased 

 her species, for five young ones were found in the cage with her. Three of 

 these are now alive and have grown considerably. They are very pretty 

 little things and have shining iridescent heads like their mother, towards 

 whom, strange to say, they most decidedly show an affection and liking, being 

 never found many inches away from her side." 



The following is a description of the Smooth Snake : — It is small, seldom 

 reaching two feet in length. Above, it is of a brownish or rather greenish 

 brown colour, spotted like the common snake with black, that is with two rows 

 of black spots parallel to each other. The lower parts are lighter and some- 

 times thickly marked and spotted with black. The smooth snake may easily be 

 distinguished from the other British snakes by the perfect smoothness of its 

 scales. From the common snake it may be easily known too by the absence 

 of the bright yellow spots behind the head, and from the viper by its not 

 having the zig-zag dark stripe down the back. 

 Standlake, Witney, Oxon. 



ON THE VARIATION OF SPECIES. 



By C. W. DALE. 



In the First Volume of the Entomological Magazine (1833), concerning the 

 genus Gnophos, formerly Charissa, my father writes—" I have taken C. 

 serotinaria on a chalk soil, as in the Isle of Wight for instance, and always 

 whitish ; C. pullaria, on stony chalk at Dover, is rather darker ; and another 

 variety on Portland stone darker still, besides a variety at Monk's Wood 

 which appears intermediate. I have taken C, dilucidaria at Teignmouth, 

 between grass land and heath, and one very nearly allied on the Mendip 

 Hills, out of furze and on old walls. C. ohscuraria, which I have taken on 

 Parley Heath, is very dark indeed. Is it not possible that all these are one 

 species ? " — J. C. Dale. 



From this communication we may conclude that dark varieties occur on 

 cold wet lands, and the light ones on light dry soils which absorb a greater 

 amount of heat from the rays of the sun. In the transactions of the Entomo- 

 logical Society of London, 1882, page 503, Mr. George Lewin says, "What 

 we call bright colour does not exist in obscurity, light is necessary to appreci- 

 ate it, and is, I think, the factor which produces it, and that nocturnal insects 

 are black because they are not affected by direct rays from the sun." 



Chalk districts seem as a rule to be inhabited by insects of a bright light 



