172 Dr. H. Eltringham's Further Observations on the 



We have now to consider the special area on the hind- 

 wing. On the upper side, extending over a large portion 

 of the discoidal cell, and from the third median to the sub- 

 costal is an area covered by long scales which give it a 

 furry appearance. One of these scales is shown at PL XX, 

 fig. 34a. It consists of a long narrow section culminating 

 distally in a spatulate formation which bears numerous 

 small hair-like projections. In the discoidal cell of the 

 hind-wing there is in addition a somewhat quadrate patch 

 of greyish brown scales, which also differ from those 

 covering the rest of the surface. One of these scales, also 

 shown at PI. XX, fig. 346, is seen to be broad, with a length 

 of about three times the width, and apparently somewhat 

 thickened in the central area. 



The function of these specialised scales is obscure. 

 They are supposed to be, and possibly are, scent-scales, 

 though sections through the wing at points where they 

 occur do not show any special cells, or indeed any cells at 

 all, in connection therewith. If the insect can by any 

 means transfer scent material from its brushes to the fur 

 patch, the latter might serve as a distributing apparatus, 

 but we require greater knowledge of the living butterfly 

 in its natural surroundings before the function of these 

 patches can be established. Kershaw mentions the species 

 in the notes above referred to, and of the use of the brushes 

 he speaks as follows : — 



" Whilst flying up and down some shady pathway the 

 butterfly often everts and retracts the glands, sometimes 

 partially and sometimes fully : both when solitary and 

 when in company with others of its kind. I could never 

 be quite certain that the glands emitted any scent, though 

 doubtless they do so. A powerful odour which would 

 attract the attention of an insect might, I suppose, be 

 imperceptible to human olfactory organs. In any case, 

 the bright golden hairs of the glands are plainly discernible 

 many yards away as the insect is constantly thrusting the 

 glands out and withdrawing them." 



The only other Euploeine butterfly I have examined is 

 Tronga brookei, Moore. This species has no brands or 

 patches of special scales on the wing, and the brushes must 

 therefore perform their scent-producing functions unaided. 

 I have not thought it necessary to photograph any of the 

 sections, as they could scarcely be distinguished from those 

 of T. mulciher. The brush-bag possesses the same glandular 



