446 BRITISH LEPIDOPTERA. 



le papillon respire Fair. Ces grosses trompes ne serviroient 

 elles que de conduit au sue des plantes, les deux trous donneroient- 

 ils entree ou sortie a Fair dans le corps du papillon ?" 

 Reaumur's view appears to have been accepted without question 

 by Linne, De Geer, Schroter, and others of our earlier writers, 

 but afterwards much discussion took place and very different 

 theories as to the cause of the sound were formulated. As 

 bearing on Reaumur's view we may here note that Duponchel, 

 at one time, considered [Ann. Soc. Ent. Fr., 1839, p. 59) that 

 the sound was due to the rubbing together of the prothorax and 

 scutellum, Guerin {pp. cit., 1838, p. lv) and Landois (Zeits.f.wiss. Zool., 

 1848, p. 55) were of opinion that the rubbing of the maxillae 

 and palpi produced the sound, Van der Hoeven held {Tijds. 

 Ent. Ned., ii., pp. 117 et seq.) the same view with the modification that 

 the roughnesses at the base of the tongue rubbed against one another, 

 Rosel considered that it arose from the rubbing of the thorax and 

 abdomen, and Vallot (EInstitut, ii., p. 7) that the sound arose from 

 the movement of the wings. Nerland, however, pointed out (Insecta, 

 ill., p. 87) that the moth could stridulate when quite still and 

 without any external movement being observable, whilst Kirby and 

 Spence further note (Jntrod. to Entom., 7th ed., p. 493) that, when 

 the wings as well as the thorax and abdomen are held down, the cry 

 becomes still louder. Layard opines (Tennent's Natural History of 

 Ceylon, p. 427) that the sound made by M. satanas is caused by air 

 being passed through the stigmata of the 1st abdominal segment, 

 which, streaming out, he supposed set in motion the strong tufts of 

 bristles which cover the opening. Lorey earlier advocated (Godart's 

 Hist. Nat. de Fratice, iii., p. 18) this view, but various observers have 

 pointed out that these abdominal tufts are merely $ secondary 

 sexual characters and not connected with the stigmata. Goureau 

 states {Ann. Soc. Ent. Er., 1837, pp. 66 et seq.) that the sound 

 appears to proceed from a fold towards the base of the abdomen, 

 and later (loc. cit., 1840, pp. 125-128) it does not seem, he 

 says, to be produced by any special vocal organ, but appears 

 to be analogous with the humming sound made by diptera and 

 hymenoptera, which is produced by the vibrations of the thorax, 

 set in motion by the powerful muscles which it contains. Tremeau 

 de Rochebrune in his article {Actes Soc. Linn. Bordeaux, v., 

 17, 120, 122, 1832) on the cry of M. atropos, begins by 

 mentioning that Reaumur attributed it to the friction of the proboscis 

 against the palpi, Lorey to the air escaping through the tracheae 

 which exist on either side of the abdomen, while Passerini regarded 

 it as arising from the interior of the head, that is to say from 

 a cavity which communicates with the " faux-conduit " of the 

 tongue, where are placed some muscles which are alternately 

 lowered and raised in such wise that the former movement 

 makes the air enter this cavity whilst the latter expels it. 

 Rochebrune's own experiments led him to a different conclusion 

 from any of these. His experiments may be summarised as follows : 



1. He extended the tongue so that it could not touch the palpi, and 

 the cry continued. 



2. He carefully closed the trachea; with soft wax, yet the cry continued 

 unabated. 



