Dr. H. Eltringham on Danaine Butterflies. 153 



addition to these structures it was found that a certain 

 area of the brush-bag contained cells which produced 

 numerous delicate chitinous filaments, these having the 

 property of breaking up transversely into innumerable 

 tiny particles, thus forming a kind of dust, the suggestion 

 being that these particles assisted in the diffusion of the 

 scent.* Reference was also made to the fact that these 

 butterflies are known to apply their brushes to the patches 

 on the wings. 



Having thus briefly reviewed the conclusions already 

 attained in my previous paper, I propose to describe the 

 corresponding structures in certain other species of butter- 

 flies, and it will be seen that complicated as is the arrange- 

 ment in A. niavius, differentiation has reached an even 

 higher development in other forms. Neither wing-glands 

 nor dust-producing devices are invariably present ; the 

 brush itself and not the wing may produce the scent 

 material, or at least exhibit a glandular structure, whilst 

 the dust may be produced by the wing and not by the 

 brush, and in the pupal instead of in the imaginal state. 



I propose to describe each species separately, after which 

 the results may be considered. 



Amauris psyttalea, Plotz. 



Of this species I have had only one body to examine. 

 It was sent to me by Mr. C. A. Wiggins, who did not then 

 understand that I required the wings as well. I am thus 

 unable to describe the wing-brands except from such 

 information as can be gathered from the examination of 

 dried examples. From these, however, it is clear that the 

 arrangement is very similar to that in A. niavius. Regular 

 rows of " scent-cups " are seen, each covered by a small 

 scale arising from a socket placed between two of the 

 scent-cups in the adjacent row. The scales resemble 

 those in niavius, though they are slightly less rounded. 

 The glands are probably similar to those in niavius. From 

 the single abdomen available I was able to make both 

 transverse and longitudinal sections of the brushes, and 

 these proved extremely interesting. From the base of 

 the brush there arises a pencil of hairs corresponding in 



* This idea of the function of the dust particles was in part due 

 to the suggestion of my friend Dr. Karl Jordan, a fact which I 

 regret I omitted to acknowledge in my previous paper. 



