6 



throughout nature may have led to its adoption 

 as a danger signal by primitive man. Wagps and 

 hornets are the best example of brightly coloured 

 insects protected by stings, and we also notice 

 that all larvte with nauseous flavour, or which have 

 poisonous or urticating hairs are brightly coloured. 

 I have often tried to get our London sparrows to 

 eat the common Tiger Moth (Arctia caia), one of 

 the most brilliant insects of this country, but 

 they have always refused to do so. 



Mimicry is the imitation by one specie? of 

 another, either for the purpose of sharing in the 

 protection enjoyed by the latter owing to stings, 

 nauseous flavour, etc., or in order to enable the 

 mimic to get its food. Thus we find almost every 

 order of insects has some species that mimic the 

 well protected hornets and wasps. Among Lepi- 

 doptera, Sesia bembeciformis and S. apiformis 

 exactly resemble hornets in their transparent 

 wings, yellow and black bodies and general shape, 

 and even have the habit of turning the body about 

 and pretending to sting their captors, a feat that 

 of course they are quite incapable of performing. 

 Macroglossa fuciformis and M. bonibyliformis 

 again, with their clear wings and stout, hairy 

 bodies, resemble the humble bees, in whose com- 

 pany they fly by day over the flowers. Gnophria 

 ruhri coll is closes its black wings into a narrow strip 

 over its orange body, its coDar bemg red, and 

 tumbles out of the bushes in company 

 ■with a narrow, black, red-coUared, orange 

 bodied beetle, which, from its evil smell, must be 

 distasteful to birds. Blimicry is sometimes 

 developed in order to terrify, thus Smerinthus 

 ocellatus when at rest only shows the brown upper 

 wings, and in that position resembles a dead leaf. 

 When touched, it suddenly flings these forward, 

 revealing the hind wings which are red with large 

 eye-like spots, and this action would doubtless 

 frighten a bird. The larva Chmrorampa elpenor, 

 which has the power of making itself resemble a 

 small snake, is another instance. The third class of 

 mimics, called "aggressive," are poorly represented 

 in the Lepidoptera. One small moth, Xysttmtodoma 



nielancllti , the larva of which feeds on the combs 

 and pollen stored in bee-hives, is sometimes given 

 as an example, as it is supposed to mimic the honey 

 bee. It is certainly of a similar colour, but I can 

 see no great resemblance, and it may be possible 

 that we have here a species that is even now 

 developing into a mimic. There are some splendid 

 samples among the Diptera, the larva feeding in 

 the nests of humble bees, which the dipteroa 

 mimics very faithfully. 



But for an undoubted proof of the existence of 

 protective colouring and its formation by natural 

 selection, we must examine some of the moths from 

 the London district and lar^e manufacturing 

 centres. In these districts the large amount of 

 smoke from chimneys and factories has gradually 

 darkened the tree trunks, fences and other resting 

 places, and, in order to be the better protected, 

 many moths have developed dark varieties I will 

 specially mention one species Amphidasisbetularia. 

 The typical form of this moth from the country 

 districts is creamy white with black speckling, well 

 described by its popular name of " The Peppered 

 Moth." Some fifty years ago entomologists in the 

 great Lancashire manufacturing district noticed 

 varieties of this moth with a large development in 

 the black markings, and within a few years 

 absolutely black varieties were found, then the 

 speckled forms became rarer, and now the black 

 variety is the only one in that district. Around 

 London and some of the other smoky centres the 

 same thing is now being repeated, and we may 

 look for black varieties there with a good chance of 

 success. 



And with this notable example of colour change 

 progressing durins recent times I will conclude 

 this evening. I can only express a hope that some 

 remarks of mine will have awakened an interest in 

 this most absorbing subject. 



At the close a very hearty vote of thanks was 

 accorded the lecturer for his very interesting 

 address and for kindly bringing the splendid sets 

 of specimens to illustrate his paper. 



FIFTH WINTER MEETING.— JANUARY 26th, 1904. 



'NATURAL HISTORY PHOTOGRAPHY."— By G. F. HARRIS, Esq., F.R.P.S. 



A crowded audience assembled in the Reference history photography, such as botanical, zoological. 



Library of the Beaney Institute to hear the above 

 attiliation lecture from the Royal Photographic 

 Society. The lecture was kindly read by Miss K. 

 Sworn, and was illustrated by means of sixty lan- 

 tern slides showing various phases of natural 



entomological, etc. Many of the hints given 

 should prove of use to many of our members 

 interested in the various branches of this fascin- 

 ating study. 



-sQxyiS>^ 



