MR. TRIMEN ON MIMETIC ANALOGIES AMONG AFRICAN BUTTERFLIES. 499 



them as he would species of other families, soon finds his coUeeting-hox alive with its 

 struggling occupants. So flexible are the wings, that the insect generally succeeds in 

 withdrawing them from crossed fences of pins which form a complete barrier to any 

 motion on the part of ordinary Butterflies ; and however bent and distorted the wings 

 may become in such exertions, I have never known a fracture of nervures or membrane 

 to result, the organs resuming their natural position even after having been bent double 

 for some hours. While entomologizing in Natal, my Kafir collector used often to bring 

 me numerous examples of the commonest species in his box, and when engaged in the 

 necessary work of rejection, I constantly found tlie limp-winged Banaidce and Acrcnidoi, 

 as soon as they were released from the transfixing-pin, fly off with perfect ease and 

 apparent nonchalance. 



It is not difficult to perceive how important, as a reserve means of defence, this 

 unusual elasticity of structure may prove. That Ijirds, and other eaters of insects, may 

 occasionally capture a Butterfly of these malodorous tribes before discovering its distasteful 

 character is not an unreasonable supposition, especially in seasons when an exceptional 

 scarcity of some favourite food may prevail. In such a case it may be safely stated that 

 the chances are very greatly in favour of a Dauais or an Acrcea escaping, if not whoUy 

 unhurt, yet without serious injury, after rough treatment that would have proved fatal 

 to a harder but less elastic animal*. 



More extended observation is necessary to prove by positive evidence that persecution 

 of the Banaidce and Acrceklce has almost wholly ceased, although, negatively, the witness 

 borne by their abundance is very strongly in favour of this view. Some check upon 

 their inordinate increase must, of course, exist ; and this is probably to be found in the 

 Ichneumon flies attached to the various species, the females of which are not likely to 

 be deterred by any odour from depositing their ova in the larvte. Mr. Bates has re- 

 corded that the Heliconide Danaidcei, when at rest on leaves, did not "appear to be 

 molested by lizards or jDredaceous flies of the family AslUdce, which were very often seen 

 pouncing on Butterflies of other families." A well-known naturalist has quoted (in the 

 Westminster and Foreign Quarterly Review for July 1867, Article 1) an observation 

 l)y Mr. Belt, that a pair of Puif-birds, watched by him in Brazil, during half-an-hour 

 caught and brought to their nest various butterflies to feed their young, but entu'cl^y 

 avoided the slow-flying ^eZieo/wte, which were about the spot in great numbers J. I 



* This elasticity of structure is not confinecl to the Butterflies in question, being a character of man)- Mollis, and 

 markedly of some belonging to the families Agarislida' and Zijciamida'. It is remarkable that the thi'ec 8outh-Africau 

 Moths in which I have found this peculiarit}' most developed, viz. Pals decora, Euscmia euplumia, and Glaxicopix 

 /ora(o««— all have a strong and offensive odom-, emit drops of white or yellow fluid, and are slow-flj-ing, brightly 

 coloured, and abundant species. 



t The term used by Mr. Bates is " Danaoid EeUconida'^ ; but as it is clear that that author agrees with Dr. Felder 

 in recognizing all the so-called Hdiconidce except Helkoniiis and Eueidcs as forming a part of the ftimily Danaldce, I 

 have ventured to transpose the words in order the more distinctly to express this relationship. 



+ It is not uncommon to hear doubt expressed as to whether birds even feed on butterflies at all ; and thus the 

 case jiLst mentioned is of importance. I have noticed a Swallow chasing a Pleris Brusskcv. in England ; and 1 never 

 knew it to be disputed that the Goatsuckers cat the nocturnal Lepidoptera. But when one reflects on the host of 

 insectivorous birds in all (and especially in tropical) countries, it would be marvellous indeed if they neglected the 

 large supply of food afforded by the generally defenceless race of Butterflies. 



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