4o6 NATURAL SCIENCE. June, 



May 2, that investigator exhibited some Hving specimens of the 

 larva of the Lappet-moth {Gastropacha quercifoUa). Under usual 

 conditions these caterpillars are of a rather dark brown colour, 

 with a few whitish spots down the sides ; some may be darker, and 

 some lighter than the others. The specimens exhibited, however, 

 which had all been reared from the same batch of eggs, had been 

 divided into two lots, and, during the early stages of growth, one Ibt 

 had been surrounded by black twigs, and the other lot by lichen-covered 

 twigs, the food being the same in both cases. So impressionable were 

 the youthful caterpillars, that all the former lot had become nearly 

 black, with the white spots very few and small, while the latter lot were 

 lighter than usual in colour and had the white spots large and numerous. 

 Subsequent transference of a hght caterpillar to the black twigs, or 

 'vice versa, had had no effect upon its colouring; the response to 

 environment took place only during infancy. In the course of a 

 lantern demonstration, Mr. Poulton described many other experi- 

 ments having similar results, and expressed his opinion that the 

 young caterpillar did actually possess considerable sensibility and 

 power of adaptation to the colour of its surroundings. This sounded 

 like flat Lamarckism, but only for a moment. There was a limita- 

 tion to be noted ; there was no response to such colours as the 

 caterpillar did not ordinarily come in contact with in a state of 

 nature ; or, if any effect was produced, it was only in the direction of 

 some variation natural to the animal, and useful to it under certain 

 natural circumstances. For this reason, and because all variations 

 that do occur are clearly protective, the lecturer concluded that this 

 marvellous power of individual adaptation to environment had been 

 acquired through the ordinary processes of natural selection. And 

 that is at all events sound Darwinism. Whether the experiments 

 are yet sufficiently conclusive, will however be doubted by many 

 entomologists. 



A most interesting example of this individual adaptation, 

 regularly occurring amid natural surroundings, has recently been added 

 to the beautiful series exhibited in the central hall at the British 

 Museum (Natural History). In the forest of Maramanga, which is in 

 Madagascar, about 65 miles east of Antananarivo, there lives a 

 Homopterous insect, which men (scientific men) call Flatoides dealbatiis. 

 When this insect settles, as is its habit, on the bark of the forest trees, 

 it becomes almost imperceptible ; for each specimen, though differing 

 slightly from its neighbour, bears, when its wings are closed, a most 

 striking resemblance either to plain bark, or to bark covered with 

 green moss or grey hchen. This, as the Museum label with true 

 scientific caution expresses it, is " a fact which seems well calculated 

 to afford them protection." Madagascar has also furnished the 

 Museum with the curious beetle, Lithintis nigrocristatus, whose black 

 and white or yellowish colour and black hairs render it almost in- 

 distinguishable from the lichen-covered twigs among which it lives. 



