BUTTERFLY SOUNDS. 393 



liope to show that it is not impro))ably a common feature in the life of 

 butterflies. The first account of the noises made by butterflies (belons'incr 

 to the genus Ageronia) appears to be that given by Darwin in his cele- 

 brated Journal, who states that " several times when a pair, probably 

 male and female, were chasing each other in an irregular course, they 

 passed within a few yards of me ; and I distinctly heard a clicking noise, 

 similar to that produced by a toothed wheel passing under a spring catch. 

 The noise was continued at short intervals, and could be distinguished at 

 about twenty yards' distance " (pp. 33-34). But the most interesting 

 account we have seen of these sounds is that given by Mr. Bio-fr-Wither. 

 This butterfly, which he and his friends christened the " whip butterfly," 

 is said by him to settle upon the boles of trees, head downward and wino-s 

 outspread, closely embracing the bark. " In this position, which is more 

 common to moths than to butterflies, it remains undetected by the casual 

 observer, as it resembles merely a patch of lichen. If approached, how- 

 ever, it will give warning of its disapprobation by sharply shuttino- and 

 opening its wings once or twice (more generally twice) in quick succes- 

 sion, producing by this sudden contact the whip-like snap from which we 

 gave it its name." One notices exactly this movement in many of our tem- 

 perate Vanessidi, when half alarmed. " Frequently, too, it makes the 

 same sound when on the wing. The surugiid [a bird with a sharp beak 

 and abnormally big mouth] is very partial to this butterfly, and is at once 

 attracted by the whip-like crack, forsaking its branch on which perhaps it 

 has been perching for half an hour without having given the smallest sio-n 

 of life, and darting after the 'whip-cracker' with great eagerness.'' 

 (Pioneering in South Brazil, i : 306.) He even states that the bird 

 frequently alights upon a tree trembling under the blow of the axe, the 

 vibration of the leaves caused by the strokes of the axe deceivino- it in 

 imagining that butterflies are flitting about it. Mr. Walker (Ent. monthl. 

 mag.,xix:26) states that when these butterflies are approached after 

 alighting they start off at great speed, "making at the same time a loud 

 and most singular snapping or crackling noise, which I can best compare 

 to the sound of a slight electric sjjark, at intervals of one to five seconds. 

 This sound is particularly distinct when the male is chasing the female and I 

 have heard it at a distance of at least ten yards. I think it is produced 

 by both sexes." Wallace observed the same thing at Para and believed 

 that it was produced in some way by the contact of two insects, as he only 

 heard it when two insects were chasing or frolicking with each other, and 

 it seems to be the general belief that the sound is common to both sexes, 

 which Mr. Van Volxem positively asserts. 



But, as stated above, these sounds are emitted also by butterflies of the 

 temperate regions. Thus Mr. Swinton, who has written a good deal upon 

 this subject, states that Aglais urticae, about to hibernate and in a drowsv 



so 



