Structure of Scent Organs in Male Danaine Butterflies. 161 



section are not at first distinguishable from the yellow 

 hairs. They soon, however, begin to present a nodulated 

 appearance similar to that in ochlea, and their disintegration 

 towards the distal end of the brush produces a considerable 

 quantity of dust corresponding with that of other species. 

 It will be noticed from the sections that the black hairs in 

 this species are of comparatively small diameter, and that 

 they arise from an area of the brush-bag which is greatly 

 thickened by the aggregation of small trichogenic cells. 

 PI. XIII, fig. 6, is a longitudinal section of this area. 

 PI. XVIII, fig. 13, shows a section of a yellow, and of a black 

 hair, and fig. 11 represents the appearance of one of the flat- 

 tened and nodulated hairs which ultimately break up to 

 form the dust material. This disintegration occurs through 

 the gradual decrease in the lumen and the thinning down 

 of the bases of the nodules, until the latter become de- 

 tached. A longitudinal view of one of these hairs presents 

 much the same appearance as that of the corresponding 

 structure in A. ochlea. 



Amauris whytei, Butl. 



The wing-patch in this species is provided with scales 

 which closely resemble those of A. egialea, both in shape 

 and in the fact that they do not form a continuous pro- 

 tection for the upper surface of the glands. The structure 

 of the wing-patch differs from all those previously described 

 in not showing any definite differentiation into separate 

 glands. The cup-like structures occur in fairly definite 

 rows, separated by rather wide spaces representing the 

 blind-gland areas described in other species. It will be 

 seen from the section shown on PI. XIX, fig. 14, that the 

 glandular area is very thin and that the gland-cells are 

 rather irregularly placed between the wing-membranes. 

 Strands of connective tissue joining the two surfaces of 

 the wing presumably exist, although they are but little 

 evident. In this species the wing-patch is either in a 

 more primitive condition or is, so far as thickness and 

 differentiation of structure are concerned, degenerate. 



The abdominal brushes are also in some respects different 

 from those already described. PI. XIV, fig. 1, shows a 

 section of the brush near its base. The brush-bag is seen 

 to be comparatively thick. Large hair-producing cells are 

 present, and in at least two instances the central lumen of 



TRANS. ENT. SOC. LOND. 1915. — PART I. (jUNE) M 



