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the Herefordshire farmer or the pigeon fancier, by the careful’ 
‘selection of parent stock, with a view to peculiarities, whether 
structural or ornamental, being reproduced in the progeny. Of 
late years there is a tendeucy to apply this treatment in a practical 
“manner, and no doubt results of a kind approaching those obtained 
by the breeders of animals and birds, possibly even as singular as. 
‘those of the horticulturist, will be the outcome. Here are several 
varieties of the buff ermine, one of which has been recently 
‘produced in this manner, and another evidently the offspring of 
the crossing of a variety peculiar to York with another peculiar to 
Heligoland. These have been kindly lent by my friend Mr. H. A,. 
Auld. 
Let us now enquire why it is that a species when isolated,. 
restricted to a limited area, and separated from the parent stock, 
‘shows this tendency to variation. The answer would appear to be 
that the surroundments, such as natural enemies, soil, food,. 
climate, and other atmospheric conditions, differ from those to- 
which it had been previously accustomed. First, take natural 
enemies; to counteract the evils of which natural selection and 
‘mimicry come so prominently into play, as has already been ably 
explained to you by our friend Mr. Stuart Hills, and which therefore - 
‘requires no repetition on my part. But there is one curiosity in 
connection with non-fatal injuries of enemies, to which I should 
like to call your attention; it is that when the damage done by 
ichneumon or other assailants, or by accident, to a caterpillar or- 
chrysalis is insufficient to kill, though serious enough to cause: 
destruction of portions of the wing in the perfect insect, a new 
fringe is grown on the mutilated edges of the wound. This is: 
mentioned as a curiosity, not as a variation. Another very inte- 
‘resting point is mentioned by Dr. Chapman in the ‘‘ Entomologist ;” 
it is that injury to the chrysalis by pressure will cause the portions 
suffering from this rough treatment to become bleached in the 
“perfect insects, and he instances the case of a red admiral chrysalis. 
thus accidentally squeezed, in which a white patch crossed the red. 
‘band of the upper wing of the perfect insect, and a corresponding 
‘change was evident on the lower wing. This cause of bleaching 
may possibly account for the mysterious white blotches so 
frequently noticed on the wings of the meadow brown—a condition 
which has usually been accounted for by sun burning. 
Then the soil has been supposed to exercise a chemical action. 
through the vegetation of the locality in such a manner as to. 
“produce dark varieties on a peaty soil and pale ones on the chalk ;. 
but all sorts of chemicals and dyes have been tried without 
producing any appreciable effect upon the adult insect; at most, 
semi-transparent caterpillars have shown a blush of the colour 
