130 Dr. G. B. Longstaffs Notes on the Butterflies 



I have satisfied myself from observations on English 

 Satyrids that the attitude is more often adopted by the 

 butterflies when sitting in sunshine than in shade. Now 

 if the list be away from the sun the shadow would be 

 increased, but if towards the sun it would be diminished, 

 in some cases even to extinction. Numerous observations 

 are required to determine whether the list has any relation 

 to the sun's position. I would however remark that in the 

 case of a butterfly with cryptic colouring on the under-side 

 the shadow is in many cases far more conspicuous than 

 the butterfly itself, as I frequently observed in India. 

 Obviously, therefore, economy of shadow might be a 

 considerable protection. Now, near Simla in October, 

 1903, in the case of Pararge shaJcra, a butterfly closely re- 

 sembling P. meg/era, I noted three individuals in succession 

 settled with their backs to the sun so as to reduce the 

 shadow to a mere line. This was unfortunately just as I 

 was leaving the locality where the species occurred, but I 

 did not observe any instances to the contrary. I should add 

 that in P. shaJcra I looked for, but did not find any list* 



Scents in Butterflies. 



Owing to the imperfections of the human nose these are 

 very difficult to detect and to describe, nevertheless certain 

 definite results were obtained. 



* Since the reading of the paper Prof. Ponlton has called my 

 attention to the following interesting observation by Mr. E. E. 

 Green. " M. ismene is an adept at concealing itself. It usually 

 pitches amongst fallen leaves where its form and coloration are 

 sufficient concealment. But even on bare ground the insect is often 

 extremely difficult to localize, though the approximate spot may have 

 been carefully noted. I have watched the fly, immediately after 

 pitching, alter its position so that its axis is directed towards the 

 sun, thus casting no shadow." — "Notes on some Ceylon Butterflies, 

 Spolia zeylanica" vol. ii, pt. vi, Aug. 1904, p. 76. 



For the following reference I am also indebted to Prof. Poulton : — - 

 Prof. G. H. Parker has clearly established that in the United States 

 when Vanessa antiopa, L., after a flight settles in full sunshine with 

 wings expanded, it speedily so adjusts its position as to place the axis 

 of the body as near as may be parallel to the sun's rays, with its head 

 turned away from the sun. Some of the genus Grapta have the 

 same habit. He thinks they do this to display their colouring to the 

 best advantage. The bearing of his interesting observations on the 

 cryptic attitude of Satyrids is that they prove decisively that a 

 butterfly can acquire the habit of definitely orienting itself. If one 

 can do this for one purpose, another species may do it for a different 

 purpose, e.g. concealment. Mr. Parker gives a Bibliography of the 

 subject. — "Mark Anniversary Volume," Cambridge University, Mass., 

 U.S.A., Article xxiii, p. 453-469, 1903. 



