294 THE CAUSES WHICH 



Lin., conjointly drops off the richer imicolorous appearance its 

 protecting surfaces show among the stones of Spain and Calabria, 

 and in Central Europe becomes sharply spotted with mossy 

 brown. Others in advancing northwards are seen to again recoil 

 from sight, having their markings obscured and obliterated with 

 sombre and earthy tints before the species finally takes its leave 

 in the starved and ungenial clime. Either phenomenon may 

 doubtless be referred to what we understand as the phases of 

 .melanism, as I find on comparing specimens of the active little 

 Red-legged Grasshopper from the heather of Western Scotland 

 and the cornfields of Italy, that in both cases the elytra are often 

 black and the hind legs reddish and unspotted ; but that the red 

 in the southern negro is far the richer of the two. Proximity 

 to the seaside is another inducement to melanism, and individuals 

 here and elsewhere are often found wholly or in part of an 

 unnatui-al roseate colour. Respecting a dark-saddled Leaf -cricket 

 deprived of leaping power, found by Rambur lurking beneath 

 the stones that fringe the picturesque snows of the Spanish Sierra 

 Nevada, Fischer, in his " Orthoptera Europea,^" remarks : — " The 

 obscure colour in this kind is unusual, and corresponds to the 

 observations of Professor Heer, who has found that beetles with 

 metallic hues become opaque and obscure on the tops of the 

 Helvetian Alps.''' 



There are some other chromatic changes advocated by this 

 systematic writer that might appear to us at first sight hardly 

 creditable, namely, that a locust should have hind-wing pigments 

 like climatic litmus paper, so as to appear in some examples of a 

 bright red, while other specimens should come to hand with 

 bright blue wings. Yet' he admits this tacitly in describing the 

 Variable Oedipoda of Pallas, which seems to assume the latter 

 cold hue on passing eastward to the wide plains of Russia and 

 Siberia; and he more than asserts it in regard to the common 

 crimson-winged 0. fasciata of Siebold. Of this butterfly-like 

 creature the starchy-coloured variety is deemed the more nor- 

 thernly form, but in parts of Central Europe acidulated wings 

 c»f blood cinnabar are seen commingling on the hills with those 

 of blue and bluish-green, which, as we reach the warm southern 

 peninsulas, cast off this disguise and turn to love's proper hue — 

 a rich rosy crimson. And it may be further remarked that of 



