440 THE INSECTA. <§. 345. 



The true Neuroptera, in all their states, have a pretty simple trachean 

 system provided with two lateral trunks. But with the Orthoptcra, on the 

 contrary, this system is usually very complicated. It is, indeed, less so 

 with the Blattidae, Forficulidae, Ephemeridao, and Perlidae ;*'•" but with 

 the Libellulidae, the two lateral trunks are very large and arise from the 

 trachean branchiae together with two other trunks.^''"'' With the other 

 Orthoptera, the tracheae are very numerous and disposed according to the 

 eecond type or form, their trunks being connected by a multitude of volu- 

 minous, longitudinal, and transverse anastomoses, giving the whole a reti- 

 culated aspect.'''" With the Acrididae, most of the transverse anastomoses 

 have large air-reservoirs on their course. '^'^^ 



With tlio Coleoptera, the tracheae are always highly developed, and 

 disposed, with the larvae, after the first type, but with the imagines, after 

 the second. '^^> With these last, the anastomosing canals, which connect the 

 primary trunks, are often double. <'"> With the Palpicornes, and Lamelli- 

 cornes, this system is most highly developed, — the fine as well as the 

 larger tracheae having a multitude of terminal vesicles.^*' 



CHAPTER VIII. 



ORGANS OF SECRETION. 



/. Urinary Organs. 



§ 345. 



The Malpighian vessels, which are widely spread among the Insecta in 

 all their conditions, •'' must now, since uric acid has been detected in their 

 secretion, be regarded as Kidneys.'-' 



W See Swammerdamm, Bib. der Nat. Taf. XIV. sels ; see Ramdohr, Verdauungswerk. d. Insekt. 



and Caru.?, Entdeck. &c. Taf. III. (larva and pupa p. 198, Taf. XXVI. and L. DufouT, Kecherch. 



Of an Ephemera). = sur les llemipt. p. 116, fig. 114. I have been 



15 Suckoiv, in Hettsinger's Zeitsch. II. Taf. I. unable to find them with the Strepsiptera in their 



II. (larva and imago of an Aeschnd). various stages of develojjment. The male imagines 



IG With the Locustidae, Achetidae and Mantidae ; of Xenos Rossii, alone, have presented to me, at 



see L. Diifour, Recherch. sur lea Orthopt. &c. p. the extremity of the digestive canal, a singular 



269, PI. I. fig. 1 (Oedipodii), and Marcel de Serres, glandular appendage resembling a crilirilorm lobe, 



Mtm. du JIus. IV. p. 331, PI. IV. (16) {Mantis), and which serves, perhaps, as a urinary organ, 



also in Isis, 1819, p. 627, Taf. IX. 2 For a long time the Malpighian vessels were 



V Marcel de Serres, loc. cit. PI. III. (15) regarded as biliary organs, when Rengger ex- 



{Truxalis), and L. Dufour, loc. cit. PI. I. {Oedi- pressed the opinion that they were urinary organs. 



poda). without, however, having demonstrated the pres- 



IS See Burmeister, Trans. Entom. Soc. I. PI. cnce of uric acid in their secreted product (Phys- 



XXIV. fig. 9 (larva of Calosoma sycophanta), iol. Untersuch. uber die Ilaushalt. der Insekt. 



and Audouin, Ann. d. Sc. Nat. IX. 1826, PI. 1S17, p. 27). This chemical proof was furnished 



XLIII. fig. 3 {Li/tta vesicatoria). by Brusnatelli and Wurzer {Meckel's Deutsch. 



I'J See L. Dufour, Ann. d. Sc. Nat. VIII. 1826, Arch. II. 1816, p. 629, and IV. 1818, p. 213), with 



p. 23, PI. XXI. bis. fig. 1, and Pictet, M^m. de liombyx inori. Subseiiuently, the existence of this 



Geneve, VII. p. 397, fig. 6 {Uammaticherus acid has been confirmed by Chevrcul with Melo- 



heros). lontha vulgaris {Straus, Consid. &c. p. 251), 



■M Swammerdamm, Ti\h. der Nat. Taf. XXIX. imihy Audouin viiih Lucanuscervus unii Polis- 



flg. 9 {Geotrupes nasicornis), and Straus, Con- tes gallica (Ann. d. Sc. Nat. V. 1836, p. 129). 



Sid. &c. PI. VII. {Melolontha vulgaris). See, See, also, AfecA-c/, Ueb. die Gallen — und Ilarnor. 



also, fur the Coleoptera in general, L. Dufour, gane der Insekten, in his Arch. 1826, p. 21, and 



Ann. d. Sc. Nat. VIII. 1826, p. 22. Gro.ilians, De System, uropcet., quod est Kadiat. 



1 As yet only Coccus, Chermes, and the Aphi- Articulat. et Mollusc. Acephalorum. 1S:J7, p. 39. 

 didae, have been found wanting the Malpighian ves- 



