246 THE COLOUKS OF ANIMALS 



also been modified, so as to produce a more or less 

 perfect resemblance to some stinging Hymenopterous 

 insect. 



ITimicry of Hymenoptera by Lepidoptera 



This is the case with two of the hawk-moths, called 

 Bee Hawks (Sesia fuciformis and S. homhyliformis) , 

 which in some degree suggest the appearance of 

 humble-bees. The habits are, however, entirely dif- 

 ferent, and the resemblance very imperfect — so much 

 so that a lizard (Lacerta muralis), to which I offered a 

 living specimen, was not imposed upon in the least, 

 but devoured the insect without hesitation or caution. 

 Although humble-bees are eaten by lizards, they are 

 always seized cautiously, and disabled before being 

 swallowed. 



In one respect these Bee Hawks are extremely in- 

 teresting, for they provide a conclusive answer to those 

 who believe that such mimetic forms have not been 

 modified from a condition which is more characteristic 

 of the group to which they belong. When the Bee 

 Hawk emerges from the chr3'salis its wings are even 

 now thinly clothed with scales, which are shaken off 

 in its first flight. The history of the change is still 

 recapitulated, as in so many other cases, in the history 

 of the individual. 



The two Hornet Clear-wing Moths (Sphecia api- 

 formis and S. bevibeciformis) afford far more perfect 



