230 ENTOMOLOGY 



of the body being light in color and inconspicuous by contrast 

 with the black. Indeed the various means by which a super- 

 ficial resemblance is brought about between remotely related 

 insects are often extraordinary. 



Irrespective of affinity, insects of diverse orders may con- 

 verge in wholesale numbers toward a central protected form. 

 The most complete examples of this have recently been brought 

 to light by Marshall and Poulton, in their splendid work on 

 the bionomics of South African insects, in which is given, for 

 instance, a colored plate showing how closely six distasteful 

 and dominant beetles of the genus Lyons are imitated by nearly 

 forty species of other genera a remarkable example of con- 

 vergence involving rio less than eighteen families and five or- 

 ders, namely, Coleoptera, Hymenoptera, Hemiptera, Lepidop- 

 tera and Diptera. Excepting a few unprotected, or Batesian, 

 mimics (a fly and two or three beetles), this association is 

 one between species that are already protected, by stings, bad 

 tastes or other peculiarities. In other words, here is Miiller- 

 ian mimicry on an immense scale ; and if Miillerian mimicry 

 is profitable when only two species are concerned, what an 

 enormous benefit it must be to each of forty participants ! 



Strength of the Theory. Evidently the theory of mimicry 

 rests upon the assumption that the -mimics, by virtue of their 

 mimicry, are specially protected from insectivorous foes. Un- 

 til the last few years, however, there was altogether too little 

 positive evidence bearing upon the assumption itself, though 

 this was supported by such scattered observations as were 

 available. The oft-repeated assertion that this lack of evi- 

 dence was due simply to inattention to the subject, has been 

 proved to be true by the decisive results recently gained in the 

 tropics by several competent investigators who have been able 

 to give the subject the requisite amount of attention. 



From his observations and experiments in India, Frank 

 Finn concludes : 



" i. That there is a general appetite for butterflies among 

 insectivorous birds, even though they are rarely seen when 

 wild to attack them. 



