THE COLORATION PBOBLEMS. 57 



The Coloration Problems. 



By W. PARKINSON CURTIS, F.E.S. 



These remarks are intended in some measure as a reply to the 

 paper published by Mr. Colthrup in the May, 1912, number of the 

 Ent. liecord (page 124, et scq.), and the further paper by Lieut. -Col. N. 

 Manders in the July-August, 1912, number (page 171, ct scq.). The 

 tardiness of my rejoinder should be explained. I bad penned an article, 

 and it actually got as far as a printer's proof, when the impending 

 publication in the IVans. Ent. Soc. LomL, (1912), page 445, et sc/j., of 

 Lieut. -Col. Manders' results of temperature experiments on 77 ///;oZ/;//7jfl.s 

 iiiisippits and l>anaida {lAiimas) chriisippuii rendered it desirable in the 

 view of the Editorial Committee that I should consider those results 

 before publishing my remarks. As is the way in these matters it was 

 difficult to follow Lieut. -Col. Manders' argument without reference to 

 the Proc. Zool. Soc. LiDidoii, (1911), page G96, ft se<j., where he has 

 expressed his views at length, and this likewise led me to read Mr. K. 

 L Pocock's Reyiiilta of E.r/icfiiiwnts on page 809, et secj., of the same 

 publication, and to reread Prof. Poulton's /■^ssai/s on Erolution. The 

 perusal of these papers led me to consider it desirable to extend and 

 modify my original remarks, both out of respect for the industry and 

 ability which Lieut. -Col. Manders had expended on experiment, and as 

 a recognition of the fact that the evidence he has brought forward is 

 in some respects contrary to my own experience, and in others not 

 helpful to the establishment of the coloration theories on that firm 

 basis of evidence that those of us who believe in them would like to 

 have. 



I hold strongly that the contested theories are the only correct and 

 natural explanations of the observed phenomena ; but the attacks upon 

 them have revealed weak spots in the arguments deduced in their 

 favour, and have shown that in some respects the evidence is slender 

 or negative; therefore when possible one should justify one's faith by 

 examples fresh from the field, rather than by logic evolved in the 

 laboratory and the museum. 



It is a little difficult to make an effort to reply to various different 

 papers and yet retain some logical sequence to one's own remarks. 

 However, at the risk of making this seem very disconnected, I shall 

 deal with the matters 1 have to remark upon in the order in which 

 they come in the papers referred to, simply remarking that I do not 

 pretend, or assume, that I have dealt with the papers fully or 

 adequately. 



With regard to Mr, Colthrup's photographic test, I would remark 

 that that is a very bad test as a rule, unless an infinitude of care be 

 expended. The record on a photographic plate is one of luminosity 

 value and not of colour or even monochromatic values as affecting the 

 human eye. An autochrome photograph would be a far better test 

 than an ordinary plate, but there again the human eye (and probably 

 the avian eye) perceives shadow as being a different colour to that 

 recorded by, and relieved with a greater abundance of detail than shown 

 in the photograph. This is so even when one uses the best panchro- 

 matic plates manufactured and the most perfectly adjusted orthochro- 

 matic screens, I know by experience, that to secure any detail in 

 March 15th, 1913, 



