256 THE KSSEX FIELD CLUB. 



beautiful series of lantern-slides, many of them being coloured, and some 

 were striking examples of the new three-colour process of photography. 



It is impossible to give in a short space, and without illustrative figures, 

 a report which would do justice to Prof. Poulton's admirable exposition of 

 a difficult subject. His remarks and examples extended over almost the 

 whole range of the theories of Mimicry of Bates and MuUer among butterflies. 

 Protective Resemblance among caterpillars and other insects, and Agressive 

 and Protective Resemblance amongst crustaceans, reptiles, &c. Many striking 

 instances of "Warning Colours" were shown, and the speaker especially 

 dwelt on the expansion of the theory of common warning colours of Miiller 

 brought about by the recent observations of Messrs. Marshall and Shelford. 

 Prof. Poulton also described the remarkable discovery of the American artist, 

 Mr. Thayer, which is illustrated in the models of birds in the British Museum 

 and in the Hope Museum, showing that the light colour of the under sides of 

 many birds and animals serves to practically render them invisible when 

 illuminated from above, as in nature. The lecturer suggested that these 

 models should be reproduced«in the Club's Museum. 



The President, in proposing a vote of thanks to Prof. Poulton for his 

 admirable lecture, said that they were particularly indebted to that gentleman 

 for having taken the trouble to come up from Oxford for the purpose of 

 addressing tlie Club, this being the third occasion on which the Hope 

 Professor had given them the pleasure of hearing from him the results 

 of his continued investigations in that field of biology which he had cultivated 

 with such distinction. The lecturer had referred in the course of his remarks 

 to his own (the president's) contributions to this subject, but he thought that 

 the best contribution he had ever made was the discovery of Prof. Poulton 

 himself. Referring to the different subjects dealt with by the lecturer he 

 emphasized the point so well brought out by the magnificent illustrations 

 shown, viz., that it would appear as though natural* selection had been at 

 work with an eye to artistic effect, picking out every detail of colour, pattern, 

 structure and attitude that could be made use of in adapting the animals to 

 their environment. It was impossible to say whether a species harmonised 

 with its surroundings unless it were seen under natural conditions, and large 

 and apparently conspicuous animals, such as zebras and giraffes, had been 

 shown to be really well adapted for concealment when among their natural 

 surroundings. He (Prof. Meldola) went on to say that he was glad of the 

 present opportunity of being able to make a public recantation of a view 

 which he had many years ago first broached at a meeting of the Essex Field 

 Club. He referred to the light or white colours of the undersides of birds and 

 animals. At the time when this subject was being discussed by the Club 

 (see Proc. E.F.C., vol. I., p. vi., and discussion in Nature, vol. 31, p. 505 and 

 32, p. 172) he had not realised that such an arrangement of colours could 

 possibly have the enormous effect in affording concealment that had now been 

 shown to be the case by the American artist, whose models of ducks in the 

 Natural History Museum at South Kensington and in the Hope Museum at 

 Oxford, of which Prof. Poulton had shown them photographs, were well worth 

 lookin" at. He thought that their own Museum ought to possess such models, 

 which were not very difficult to make. 



