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



of irregular section towards their distal extremities. Some 

 hairs contain particles of a brown secretion, which appears 

 in the photographs as a blackening of the section. PI. XX, 

 fig. 38, is a section of one of the hairs at about the middle 

 of its length, showing the contained granules, whilst fig. 39 

 taken nearer the distal end is without these. Fig. 37 is a 

 surface view of one of the hairs somewhat beyond the 

 middle of its length. The hair is covered with projections 

 having a curious form, their outer surfaces bearing delicate 

 ridges and their extremities produced to fine points. 

 PI. XX, fig. 36, shows the appearance of the glandular cells 

 of the main brush-bag. It is scarcely possible to decide 

 how many cells belong to each hair-socket. Possibly the 

 number may vary. I have here shown three, since in the 

 preparation from which the drawing was made three cells 

 could be recognised with some certainty as attached to 

 this particular socket. Beneath the entrance of the hair 

 is a rod of protoplasm usually staining rather darker than 

 the rest, and surrounded by vacuoles. The cells are very 

 finely granulated and contain large and conspicuous nuclei. 

 There is no dust material in Hestia lynceus. The absence 

 of wing-glands and the glandular structure of the brush 

 indicate that the scent-material is produced by the latter, 

 being apparently secreted by the cells and discharged into 

 the interior of the hairs. Thence it must make its way 

 to the exterior, and doubtless openings exist, although I 

 have not been able to discern them. It is possible that 

 the passages, which must be very minute, may be hidden 

 by the projections on the hairs. 



Summary. 



In the foregoing pages I have endeavoured to describe 

 as concisely as possible the actual structure of the remark- 

 able organs associated with the production of scents in a 

 few species of tropical butterflies. It may be objected 

 that in no case is there any direct evidence that a scent 

 is produced at all. Such evidence cannot, however, be 

 expected from examples which, for histological purposes, 

 have been subjected to the chemical action of preservatives. 

 It is furthermore to be admitted that Mr. Kershaw working 

 in the field could detect no actual scent in T. mulciher. 

 Nevertheless, we know from the observations of Fritz 

 Mliller, Dixey, Longstaff, and others that very many 

 Lepidoptera do produce scents perceptible to the human 



