^52 



NATURE 



\yune 20, 1872 



to speak. This experiment disproves absolutely all theories which 

 connect the sound with the abdomen in any way, by friction or 

 otherwise. He next removed successively from a molh the palp^ 

 the trunk, and the spallettc, and the insect nevertheless continued 

 to squeak. lie then cut away carefully with a sliarp knife the 

 horny top of the head of anotlier specimen, and observed certain 

 muscles rising and falling in rapid motion when the animal 

 squealced, but remaining quiescent as soon as the sound ceased. 

 As long as these muscles were left intact the insect might be 

 mutilated in almost any manner without the sound being stopped. 

 If these muscles were divided longitudinally, or transversely, the 

 power to emit sound was lost. In quite a fresh specimen, he says, 

 in examination after death, the upper part of the head is found filled 

 with an indurated cellular structure, and beneath this are fouml 

 the elevating and depressing muscles. Beneath these is an inclined 

 shining horny surface of triangular form leading to a narro.v 

 transverse aperture corresponding with the opening of the pro- 

 boscis tube. At the bade of the incline is a very fine aperture, 

 leading into the body of the Spliinx. He concludes that the 

 a'r enters the cavity of the head by the fine aperture, and is 

 driven out through the narrow transverse one by the action 

 of the muscles just described, and tiiat thus the sound is 

 prodaced. 



Chav.annes wrote on the subject (.\ct. .Soc. Ilelv. Sc. Nat. 

 17 ; Isis : Geneve, 1S32, pp. 93-94), Init I have not been able to 

 refer to his memoir, nor to that of Rochebrane (Act. Soc. Scient. 

 Bordeaux, 1832, t. 5, pp. 120-122, tab. I.) Then we have II. 

 Burmeister (Handbuch der Entomologie, Berlin, 1832), who 

 after citing Reaumur and Rossi says, " This much is certain, the 

 organ of voice is seated in the head." Then Vallot (L'/iis/iliif, 



1534, II., No. 34, p. 7), who demolishes to his own satisfaction 

 all previous theories, and adopts that of Johet, which considers 

 the sound to be produced by the striking of the wings in rapid 

 movement against certain parts. Wagner (Miiller's Archiv fiir 

 Pliysiologie, HI., 1836, pp. 6062), after satisfying himself that 

 the sound came from the head, unrolled the trunk, and found that 

 the sound became feebler, but did not cease. When he held the 

 two halves of the trunk apart, or cut off one or both up to the 

 b.ise, the sound ceased. He found just in front of the true 

 stomach a crop very large, distended with atr, and filling up the 

 whole anterior part of the abdomen, and opening into the pos- 

 terior extremity of the cesophagus. He could not find any 

 special apparatus in the trunk, but he says that there appears to 

 be a fine slit-like opening at the basis of this organ on its inferior 

 surface, formed by the imperfect closure of the two halves of the 

 trunk. This may have something to do with the matter. He 

 could not find Passerini's cephalic cavity. The proboscis has 

 strong, transversely-striated muscles. Duges (Praite de Pliysio- 

 logie comparee, par A. Duges : Montpellier, 1S38, vol. ii. p. 226) 

 ascribes the noise to the rubbing togedier of the opposed edges 

 of the two halves of the proboscis. 



We have theories already in abundance, and there are more 

 yet to come ; but we now come on repetitions of previous 

 theories by persoiis who either had not access to, or were 

 too lazy to consult, the writings of the original inventors of 

 them. Dr. Alex. V. Nordman (Bull. Acad. St. Petersburg, 



1535, t. 3, pp. 164-193) says the sound is seated neither in 

 head nor proboscis, but in the abdomen ; and he then pro- 

 ceeds to give an elaborate description of the peculiar organs 

 already discovered by M. Lorey, and he congratulates himself 

 not a little on his having been able, after the failure of so many 

 ]jrevious investigators, to make this discovery, and to set the matter 

 finally at rest. We next have observations and experiments 

 made by MM. Duponchel an I Guerin (Ann. Soc. Ent. France, 

 1839, t. 8, pp. 5965). To show that Passerini w.^s wrong, 

 they compressed the trunk at tlie base shirply with forceps, 

 and also stopper! the end of the proboscis, liut apparently 

 in a very insufficient manner. The noise did not cease. 

 They had only one individual on which to operate, and there- 

 fore could not afford to mutilate it and repeat Passerini's ex- 

 periments. Their conclusion is that the noise has the nearest 

 analogy to that emitted by Longicorn beetles, whicli is produced 

 by the rubbing of the prothorax against the smooth portion of 

 the scutelliim. Goureau (Ann. Soc. Ent. France, 1S40, t. 9, 

 pp. 125- 12S) says, " Re.aumur, Passerini, Lorey, all are wrong. 

 There is no special org in for the .sound. Tlie sound is of a 

 double nature. There is one shrill part of the sound which 

 proceeds from the vibrations of the thoracic rings ; in another part 

 a grating sounrl is caused by the rubbing of the shoulders 

 against the thorax." Abicot (Ann. Soc. Ent. France, ser. 2, 



1843, t. I, Bull. p. 50) says that amputation of the trunk stops 

 the noise, therefore Goureau is wrong. 



Giuliani (.\nn. Soc. Ent. Fr., ser. 2, 1S44, t. 2, Bull. pp. 72, 75) 

 comfirms Passerini. He cut off the head and the sound stopped. 

 He held the trunk horizontally, and at various inclinations, the 

 sound continued ; he removed tlie palps, the sound continued ; 

 he dipped the head in oil, the sound ceased. He then amputated 

 the trunk at its root. Three apertures were formed by the 

 operation, one corresponding to eacli lialf of the proboscis, the 

 other probably to the prolongation of the buccal cavity situate 

 just above the trunk, and opened by the knife when amputating 

 the trunk. A green liquid flowed fro:n tlie third opening over 

 the cut root of the trunk, in which liquid large bubbles were 

 seen to be formed by the expiration accrnnpanying each sound. 

 On closing the apertures the sound ceased. He is unable to ex- 

 plain how inspiration and expiration are m.anaged. Paris (Ann. 

 Soc. Ent. France, ser. 2, 1846, t. 4, Bull. pp. 96, 142) thinks the 

 noise due to a mucous fluid which the insect forces by aspiration, 

 with the assistance of the palps up and down inside the proboscis, 

 comparing the process to the flow and reflow of a liquid in a 

 suction and force-pump. 



J. Vander Hoeven (Tydschr. Entom. Neder Vereen, 1859, t. 2, 

 Stiijk 4, pp. 1 17-122) says the source of the sound is certainly in 

 the head. In an Indian species oi Achci\mtia he has found tubero- 

 sities all over the basal portion of the trunk. The exterior sur- 

 face is beset with stiff bristles. On rubbing this surface against 

 the edge of a piece of paper or scalpel, a sound like that of the 



c.\l section through the median line of the head of A. at>-o/>os, from a 

 cimen preservecf in absolute alcohol, .-i, dome-shaped cjivity of Pas- 

 ini. B and C, depressing and elevating muscles of this cavity. Z>, 

 row orifice, leading from the civity to the tube of the proboscis. J?, 

 palpus. 



moth is produced. He considers the moth's cry to be due 

 to friction of this kind. 



Westmaas (Tydschr. Entom. Neder Vereen, 1S60, t. 3, 

 pp. 120-124) extended the trunk on a pin, and at the same time 

 pulled the palps aside. He still heard the sound, though it 

 became feeble. He cut olTthe palps without elTect on the sound. 

 He cut off the truak bit by bit, as it was gr,adually shortened the 

 sound diminished. A fluid exudation covered the enrl of the 

 trunk, and he saw bubbles of air formed in this as each sountl 

 wasemitted. He confirms Passerini. He notices that the in- 

 sect produces a louder sound when the trunk is coiled up. The 

 motli when emitting a soimd elevates the front of its body, and 

 uses an evident effort. He stopped the aperture of the trunk 

 with grease, the crying ceased ; he kept one specimen half a d.ay 

 with the trunk aperture thus closed, it emitted no sound, but on 

 the grease at last being removed squeaked at once. In order to 

 test Wagner's theory, he squashed out the abdomen ijuite flat, so 

 as to destroy any air cavity it miglit contain ; the animal still 

 squeaked. Chapronnier (.\nn. Soc. Ent. Belg. Coinptcs Rc-iiJns, 

 pp. 16, 17) says that the noise produced by tfie larva is due to 

 the snapping together of the mandibles. An imago, which he 

 bred, which had a deformed head, emitted no sound ; therefore 

 the sound organ is situate in the head. 



