THK l■;^T()^f()^()(;lsT s kkcohii. 



to Algiciras ; about half the distance was ihrough the coik ■woods over 

 level gi'ound, some part of it marshy and the other half over cultivated 

 country. This was a most disappointing day, as it was bright and 

 sunshiny, warm without being too hot, but there was hardly an insect 

 to be seen anywhere. 1 took two specimens of Hiiinicia p/ilaeas var. 

 cletis, just out in perfect condition, a specimen of AbrarKs /lantaria 

 caught in a spider's web. an example of Ant/imrcra hoi'lira and one 

 FafU iocompa xtohilis. 



The Value of Protective Resemblance in Moths. 



By LiicuT.-Coi,. N. MANDERS, K.A.M.C, F.E.S. 



Mr. Colthrup, in the May number of the Knt. Hcvonf, has raised an 

 important question by his article on " /'alia c/ii and Protective Resem- 

 blance." For many years past a controversy has been carried on 

 regarding the edibility of butterflies and the attacks of birds, and the 

 assumption that these occur, and to such an extent as to produce a 

 serious struggle for existence, has been the cause of the founding of 

 two most interesting and important theories of mimicrv bv Bates and 

 Muller. 



A serious objection to them has been the assertion, often vigorous, 

 that bird.s seldom attack butterflies, and in view of this Mr. Guy 

 Marshall, a well known suppoi'ter of both theories, collected all avail- 

 able evidence and published it in '/'ranx. Hut. Sec. LmuL, 1909, p. 329. 



Gonflning ourselves to the English l)utterflies, some sixty in num- 

 ber, he ascertained that fifty per cent, were known to be attacked, and 

 there is little .doubt that in the other fifty their rarity was the cause of 

 no observations being made. The interesting point was that no selec- 

 tion in the choice of victims was apparent, and there was no record 

 that any species of bird, with the possible exception of the Kestrel, 

 systematically feeds on liutterflies. For my own part I confess I am 

 of the opinion, that if any bird fed on butterflies to such an extent as 

 to produce, through natural selection, a change of pattern or colour, 

 such would ])(' known to some of our entomologictil oi- ornithological 

 students. 



Mr. Gollhru}) now goes a step further, and throws a doubt upon 

 the protective colouring of moths being produced by such attacks. 

 Certain it is that the human eye can be trained to .see moths and other 

 insects at rest which are quite unnoticed by the untrained eye, and if 

 a. human being, for his own instruction or amusement, can detect these 

 insects in their chosen environment without particular difficulty, they 

 can have little chance of escaping notice from the keen eye of a bird. 

 I am very much inclined to think, however, that birds do not observe 

 moths when at rest, and that so long as a moth remains absolutely 

 still, whatever its environment, it is not noticed by birds or reptiles. 

 The same thing occurs among animals, even large animals such as 

 elephants and Itison, as 1 can testify, arc extremely difficult to see, 

 when they keep absolutely immovable, as they usually do when 

 conscious of dangei. It is movement which is as fatal to them as to 

 the moths. 



Most entomologists have personal experience of swallows and other 

 l)irds snapping up moths, when they are beating the hedges, and that 

 moths are largely eaten l»y many birds cannot I think be doubted ; but 



