222 - CLASSIFICATION. [Chap. XTV. 



tion to similar habits of life, but has been gained for 

 the sake of protection. I allude to the wonderful 

 manner in which certain butterflies imitate, as first 

 described by Mr. Bates, other and quite distinct species. 

 This excellent observer has shown that in some districts 

 of S. America, where, for instance, an Ithomia abounds 

 in gaudy swarms, another butterfly, namely, a Leptalis, 

 is often found mingled in the same flock ; and the 

 latter so closely resembles the Ithomia in every shade 

 and stripe of colour and even in the shape of its wings, 

 that Mr. Bates, with his eyes sharpened by collecting 

 during eleven years, was, though always on his guard, 

 continually deceived. When the mockers and the 

 mocked are caught and compared, they are found to be 

 very different in essential structure, and to belong not 

 only to distinct genera, but often to distinct families. 

 Had this mimicry occurred in only one or two in- 

 stances, it might have been passed over as a strange 

 coincidence. But, if we proceed from a district where 

 one Leptalis imitates an Ithomia, another mocking and 

 mocked species belonging to the same two genera, 

 equally close in their resemblance, may be found. 

 Altogether no less than ten genera are enumerated, 

 which include species that imitate other butterflies. 

 The mockers and mocked always inhabit the same 

 region ; we never find an imitator living remote from 

 the form which it imitates. The mockers are almost 

 invariably rare insects ; the mocked in almost every 

 case aljound in swarms. In the same district in which 

 a species of Leptalis closely imitates an Ithomia, there 

 are sometimes other Lepidoptera mimicking the same 

 Ithomia : so that in the same place, species of three 

 genera of butterflies aL.d even a moth are found all 



