Ixxi 



for the changed attitude tended rather to enhance the effect 

 by increasing the resemblance to a tattered and weather- 

 beaten fragment of dead leaf. The exposed parts of the 

 advanced fore-wings harmonised with the rest of the pattern, 

 while the wider gap apparently added to the procryptic efiect 

 of the jagged margin. It was likely that change of attitude 

 in c-album was originally a preparation for flight now utilised 

 in an exaggerated form as aid to concealment. 



[Note. October 18 : — Since the last meeting the exhibited 

 butterfly had been placed in a dark cellar. When examined 

 on October 17 it was observed that the fore- wings were drawn 

 back so far as to close the narrow chink altogether. The 

 butterfly was undisturbed, but the light or perhaps heat of 

 the candle, held at six or eight inches distance, at once caused 

 a very gradual movement forward of the fore-wings and the 

 formation of a narrow cleft. The observation was only con- 

 tinued for a short time, but it was hoped that future investiga- 

 tions would determine whether there was normally a diurnal 

 change of attitude in these butterflies when exposed to normal 

 daylight and darkness during hibernation.] 



Concerning the interpretation of the movement in V. urticae, 

 as a preparation for flight, Dr. Perkins wrote on October 2 : — 

 " It may be, as you say, with regard to urticae. I think 

 they often raise the front wings without actual flight taking 

 place in the circumstances I have mentioned, but it may be 

 done with a view to flight, as sometimes it is a preliminary to 

 the wings being spread open. These may then be closed 

 again without flight taking place. 



" Of course ' Meadow browns ' and such-like raise or depress 

 the fore- wings to hide or expose the ocellus." * 



During the past season living Pyrameis atalanta and F. 

 urticae had been observed in the resting attitude, and it was 

 found that in these also the edges of the wings were slightly 

 out-turned, especially at the prominent angles, but to a far 

 less extent than in c-album. The observations were made 

 upon captured specimens at St. Helens, Isle of Wight, and bred 

 urticae at Oxford. 



* For a discussion of these movements see Trans. Ent. Soc. Lond., 

 1902, pp. 371-2,440-1. 



