284 Colour and the Struggle for Life 



naturalists in many lands ; but nearly all of them known since that 

 general awakening of interest in the subject which Avas inspired 

 by the great hypotheses of H. W. Bates and Fritz Miiller, We find, 

 however, that Burchell had more than once recorded the mimetic 

 resemblance to ants. An extremely ant-like bug (the larva of a 

 species of Alydus) in his Brazilian collection is labelled " 1141," with 

 the date December 8, 1826, when Burchell was at the Rio das Pedras, 

 Cubatao, near Santos. In the note-book the record is as follows : 

 "1141 Cimex. I collected this for a Formica." 



Some of the chief mimics of ants are the active little hunting 

 spiders belonging to the family Attidae. Examples have been 

 brought forward during many recent years, especially by my friends 

 Dr and Mrs Peckham, of Milwaukee, the great authorities on this 

 group of Araneae. Here too we find an observation of the mimetic 

 resemblance recorded by Burchell, and one which adds in the most 

 interesting manner to our knowledge of the subject. A fragment, 

 all that is now left, of an Attid spider, captured on June 30, 1828, 

 at Goyaz, Brazil, bears the following note, in this case on the specimen 

 and not in the note-book : "Black... runs and seems like an ant with 

 large extended jaws." My friend Mr R. I. Pocock, to whom I have 

 submitted the specimen, tells me that it is not one of the group 

 of species hitherto regarded as ant-like, and he adds, "It is most 

 interesting that Burchell should have noticed the resemblance to an 

 ant in its movements. This suggests that the perfect imitation in 

 shape, as well as in movement, seen in many species Avas started in 

 forms of an appropriate size and colour by the mimicry of movement 

 alone." Up to the present time Burchell is the only naturalist who 

 has observed an example which still exhibits this ancestral stage in 

 the evolution of mimetic likeness. 



Following the teachings of his day, Burchell was driven to believe 

 that it Avas part of the fixed and inexorable scheme of things that 

 these strange superficial resemblances existed. Thus, when he found 

 other examples of Hemipterous mimics, including one {Liiteva 

 macrojjhthcdma) with " exactly the manners of a Mantis," he added 

 the sentence, " In the genus Cimex (Linn.) are to be found the 

 outward resemblances of insects of many other genera and orders " 

 (February 15, 1829). Of another Brazilian bug, which is not to be 

 found in his collection, and cannot therefore be precisely identified, 

 he wrote: " Cimcir ... Nature seems to have intended it to imitate 

 a Sphex, both in colour r.nd the rapid palpitating and movement of 

 the antennae" (November 15, 1826). At the same time it is im- 

 possible not to feel the conviction that Burchell felt the advantage 

 of a likeness to stinging insects and to aggressive ants, just as he 

 recognised the benefits conferred on desert plants by spines and by 



