60 MIMICRY AND HOMOPLASY 



puzzled over this proceeding, which occurred every 

 time the butterfly settled, until he discovered the 

 reason: "the butterfly turned round so that the 

 tail of its two hind wings would almost come into 

 contact with the trunk of the tree, thus representing 

 a stalk, and the apparently dead leaf would hang 

 in a perfectly natural way, drooping downwards." 



A Mexican leaf butterfly (Tagetis mermeria), 

 according to Mr C. W. Beebe, behaves in such 

 a manner as to cause itself to be mistaken 

 at first glance, not only for a fallen but for a 

 falling leaf as well. Here also the individual 

 variation is very great, in correspondence with 

 the "variety of hues and mottlings which exist 

 among dead and withered leaves. . . . When 

 the insect took to wing it shot almost straight 

 upward, and instantly attained the highest point 

 of its flight. From here to its place of alighting 

 its course was a gradual descent — this living leaf 

 unconsciously reflecting every detail of the fall 

 of the withered bits of vegetation. And further, 

 when the butterfly alighted, it was not with a 

 fluttering and a few moments of hovering, but 

 as a leaf comes to rest, so the insect — a sudden 

 drop to the very ground, wings snapped together, 

 and the apparently dried, worm-eaten leaf leaned 

 far over to one side and swayed with every 

 breath of air." 1 



It is interesting to remark that a notion exists 

 to the effect that the constant repetition of such 



1 C. William Beebe, "Two Bird-Lovers in Mexico," Boston 

 and New York, 1905; see pp. 241-243. 



