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the Herefordshire farmer or the pigeon fancier, by the careful' 

 selection of parent stock, with a view to pecuHarities, whether 

 structural or ornamental, being reproduced in the progeny. Of 

 late years there is a tendency 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 stocky 

 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 



