60 



PSYCHE. 



[May iSSS. 



hands of a committee, composed of three 

 competent housewives, and, upon satisfac- 

 tory tests being had, cash prizes will be 

 awarded. The treatment in all cases rnust be 

 safe for handling, and in no way deleterious 

 to the person, texture, or household belong- 

 ings of any kind." 



The notice of these prizes appears in the 

 numero of Good housekeeping for 28 April 

 1S8S, but no definite time is set for sending in 

 descriptions of competing methods. 



Coloration of cocoons and pupae. — In 

 continuation of an item entitled "Mimetic 

 coloration of pupae of butterflies" in the April 

 numero of Psyche (p. 48), the following ex- 

 tracts are given, taken from reports, by Her- 

 bert Goss. of the proceedings of the' Entomo- 

 logical society of London, at the meetings of 

 2 Nov. 1887, and 7 March i888, as published 

 in the Entomologist, Dec. 1887, v. 20, p. 331- 

 332, and April 1888, v. 21, p. 119. 



"Mr. E. B. Poulton exhibited (2 Nov. 1887) 

 the cocoons of three species of lepidoptera, 

 in which the color of the silk had been con- 

 trolled by the use of appropriate colors in the 

 larval environment at the time of spinning 

 up. Mr. Poulton said this color suscepti- 

 bility had been previously proved by him in 

 1886 in the case oi Satiii-Jiia carpini, and the 

 experiments on the subject had been described 

 in the Proc. Royal society. 1S87. It appears 

 from these experiments that the cocoons 

 were dark brown when the larvae had been 

 placed in a black bag; white when they had 

 been freely exposed to light with white sur- 

 faces in the immediate neighborhood. Mr. 

 Poulton stated that two other species sub- 

 jected to experiment during the past season 

 afforded confirmatory results. Thus the 

 mature larvae of Eriogaster la?iestris had 

 been exposed to white surroundings by the 

 Rev. W. J. H. Newman, and cream-colored 

 cocoons were produced in all cases; whilst 

 two or three hundred larvae from the same 

 company spun the ordinary dark brown 

 cocoons among the leaves of the food-plant. 

 In the latter case the green surroundings 

 appeared to act as a stimulus to the produc- 



tion of a color which corresponded with that 

 which the leaves would subsequently assume. 

 Mr. Poulton further stated that he had ir.ore 

 recentl}' exposed the larvae oi Halias prasin- 

 ana to white surroundings, and had obtained 

 a white and a very light yellow cocoon — far 

 lighter than the lightest of those met with 

 upon leaves. The larva which spun the 

 white cocoon had previously begun to spin a 

 brown one upon a leaf, but upon being re- 

 moved to white surroundings it produced 

 white silk. Mr. Stainton suggested that 

 larvae should be placed in green boxes, with 

 the view of ascertaining whether the cocoons 

 would be green. He understood that it had 

 been suggested that the cocoons formed 

 amongst leaves became brown because the 

 larvae knew what color the leaves would ulti- 

 mately become. Mr. Poulton said he felt 

 convinced that the whole process was entirelj'- 

 involuntary, and that the susceptibility had 

 arisen through the action of natural selec- 

 tion." 



"Mr. W. White read (7 March 18S8) a 

 paper on 'Experiments upon the color-rela- 

 tion between the pupae of Pieris rapae and 

 their immediate surroundings,' which com- 

 prised a detailed account and discussion of a 

 series of observations carried on, at the 

 author's instigation, by Mr. G. C. Griffiths, 

 of Bristol. The various experiments were 

 intended to act as a further test of the con- 

 clusions arrived at by Mr. E. B. Poulton in 

 his paper on the subject recently published 

 in the Transactions of the Royal society ; and 

 to eliect this object different and additional 

 influences had been brought to bear on these 

 pupae, so that an analogy might be drawn be- 

 tween the two sets of results." 



The above notes are given in full, in the 

 hopes that American breeders of insects will 

 try experiments in this direction. The ex- 

 pense, both of time and money, in carrying 

 on this kind of experimenting is little, while 

 the results, if the work is carefully done, are 

 very valuable contributions to physiological 

 knowledge. (i: D. 



No. 144 was issued 13 Apr. 1S8S. 



