#'^ ^ND ^''^y/^ 



JOURNAL OF VARIATION. 



No. 8. Vol. III. August 15th, 1892. 



Scientific notes. 



Protective Resemblance.^ — I have been induced to put together 

 these few rough notes on " Mimicry " or, as I prefer to call it, " Pro- 

 tective Resemblance," from seeing in a recent number of The Field 

 Club an article by the Rev. F. O. Morris attacking the theory of 

 " Mimicry." The article in question reads as follows : — " One of the 

 fresh fancies put forth by our wise men of late years is what they call 

 ' mimicry.' It is the likeness of various creatures, especially insects 

 (as being, I suppose, the most numerous), to the objects they more or 

 less repose or live upon. There is just a sjibsfraiiit/i of truth, or of 

 apparent truth, in the notion they broach about it, and of this, advantajc 

 is at once taken to build any number of castles in the air upon it. To 

 take, first, a few examples of such instances as might appear at first 

 sight to give countenance to the supposition. There is the resemblance 

 of Leptogramma literana to the green lichen on the bole or branch of 

 an old apple tree, which is indeed most curious ; but if the eye of an 

 entomologist can detect the little insect even with this protective 

 disguise, how much more readily must that of some small bird or 

 other creature in search of its food, with the hundreds of lenses of the 

 eyes that some of them have, given them by Nature to aid them thus 

 to get their livelihood— told, though we are, that the would-be 

 captors are deceived by the similarity? But the insects by no means 

 escape in numberless cases, and thus the rule is disproved by excep- 

 tions. I do not know anything from this point of view more wonderful 

 than the likeness of the buff-tip moth {Pygcera biicephala) to a bit of 

 stem of a small branch of the silver-birch tree ; and the ends of the 

 wings, when closed, have a most exact resemblance to the end of the 

 said piece, as if cut off with a knife ; so much so, that, when I was a 

 boy some four or five years old, or a little more, I gave it the name of 

 the ' piece of stick moth.' But here is a fact for the philosophers to 

 face as well as they can. This moth, in its caterpillar state, I have 

 never known to feed on this birch,- nor on any other such (though it 



* Abstract of a paper read before the Cambridge Eiit. and Nat. Hist. Society, 

 April 29tli, 1892. 



- Mr. Morris's stock of information and power of observation must be very limited. 

 I had three l>irches in my garden stripped by the hirva; of this species in September, 

 1801.— Fn. 



