Structure of Scent Organs in Male Danaine Butterflies. 159 



striated appearance. The brush does not consist solely 

 of the yellow and black hairs, but is provided in addition 

 with a core of curiously modified structures of which those 

 occupying the centre are but little chitinised, whilst the 

 yellow and black hairs are separated by a layer of bodies 

 of irregular section extending to the outer end of the brush, 

 where they become much flattened. There is apparently 

 no apparatus for producing dust. 



Amauris ochlea, Boisd. 



In this species the wing- patch, whilst differing slightly 

 from that of A. egialea, resembles it closely in its main 

 features. The scales of the wing-brand are very similar in 

 shape, and in the same way they fail to cover the glands. 

 The cupped glands are in rows which, as in egialea, 

 alternate with rows of blind glands. In section the 

 appearance is also similar, but though the gland-cells are 

 of about the same size, the whole wing-patch is somewhat 

 thinner; hence in the cupped glands there is much less 

 space between the cells and the underside of the wing; 

 whilst beneath the cells of the blind glands there is but a 

 trace of the horizontally striated tissue. 



The abdominal brushes of A. ochlea are also very similar 

 in structure to those of egialea. There is a core of central 

 bodies surrounded by first-ring structures, and the black 

 and yellow hairs are separated by a layer of third-ring 

 bodies. These latter, however, are flatter near their 

 origin, after which they become more rounded, and finally 

 again flattened towards their extremities. These bodies, 

 together with the yellow hairs, have, however, a different 

 structure from those of egialea. Instead of being regularly 

 striated their surface is studded by immense numbers of 

 what may be termed chitinous nodules, which are very 

 conspicuous both in transverse and longitudinal section, 

 and towards the distal end of the brush undoubtedly 

 become detached, forming a kind of dust which serves 

 the same purpose as the dust produced in various ways by 

 other species. PL XVIII, fig. 8, shows a transverse section 

 of one of the hairs, whilst fig. 9 shows the appearance 

 in a longitudinal view. Not only is the outer surface 

 covered with nodules, but similar particles appear to 

 be formed within the hair. It may be noted that these 

 nodules are rather readily stained by haematoxylin. They 



