§ 839. THE INSECTA. 429 



nebrionidae, Mordellidae,*^ and most of the Hymenoptera/^' they consist 

 of two rather short, ramified tufts, often contained entirely in the head/^^ 

 Among the Neuroptera, the Myrmeleonidae and Sialidae have two simple 

 short salivary tubes, while, with the Phryganidae and Hemerobidae, they 

 are ramified and highly developed. '^"^ It is quite remarkable that there is, 

 in this respect, a sexual difference with the Panorpidae ; the males have 

 three pairs of very long, tortuous tubes, while, with the females, the only 

 vestiges of this apparatus are two indistinct vesicles.'"* Among the Or- 

 thoptera, the salivary organs are entirely absent with the Libellulidae, and 

 Ephemeridae. On the other hand, they are highly developed with the 

 Achetidae, Acrididae, Locustidae, Mantidae, Blattidae, Termitidae, and 

 Perlidae, where they consist of two, four, or six botryoidal masses of 

 vesicles, situated in the thorax, and having long, excretory ducts, beside, 

 also, often long-pedunculated pyriform reservoirs.'^* Among the Hemi- 

 ptera,'^'^' these organs are absent with the Aphididae and the Psyllidae ; but, 

 on the other hand, they are very large and of a remarkable structure with 

 the Bugs and Cicadidae. Here they are nearly always lobulated, and are di- 

 vided by a constriction into two portions, of which the upper is much smaller 

 than the lower, and often both have long digitiform processes. The excretory 

 duct divides, immediately after its origin, into two special canals of equal 

 or very unequal length, which extend, serpentinely, first, into the abdom- 

 inal cavity, and then ascend to the mouth, '^^' Beside these two constricted 

 glands, many Bugs have, also, one, rarely two pairs of simple salivary 

 tubes,"^* which are often dilated, vesiculiform, at their extremity. *^*^' The 

 salivary organs of the musical Cicadidae difi'er in many respects from those 

 of the others of this family ; for, beside the two simple tortuous tubes, there 

 is, in the head, another pair of glands, composed, each, of two tufts of short, 

 cylindrical caeca, situated one behind the other. ^^"* It is yet undetermined 



7 See Z,. Dtifour, Ann. d. Sc. Nat. IV. 1824, PI. with Ranatra, Nepa, Naucoris, Corixa, Redu- 

 XXIX. fig. 4, 5, XIV. 1S40, PI. XI. fig. 16. vius, and Syrtis. One is very long and the other 



8 See L. Dufour, Recherch. &c. p. 390, fig. 48, very short with Tetyra^ Pentatoma, Syromastes, 

 72, 109, 14S {Apis, Andrena, Pkilantkus, and Coreus, Ly^aeus, Aphrophora and Cercopis. 

 Xyphidria With tlie Hydrocorisae, above cited, the two sali- 



y With the Coleoptera, the ramified glands end vary glands are, moreover, composed of numerous 



in long, tortuous caeca ; while with the Hymenop- round secretory vesicles. In general, these glands 



tera, their extremities are vesiculiform, thereby have been regarded as composed of two vesicles 



giving the whole gland a botryoidal aspect. each of which has a proper excretory duct ; but 



10 See L. Dufour, Recherch. &c. p. 563, fig. this view is incorrect. The two excretory ducts 

 179, 184, 191, 192, 208, 209 {Myrmeleon, Sialis, are always the result of the division of a common 

 Hemerobius, and Phryg-anea). trunk which arises at the constricted point of the 



11 See Brants, Tijdschi'. voor natvirl. Geschid. gland. With Ranatra, alone, the anterior is en- 

 en Physiologie, 1839, p. 173 ; and L. Dufour, tirely separated from the posterior portion of the 

 Recherch. &c. p. 582, fig. 169 (Panorpa). gland. t 



12 See L. Dufour, Recherch. &c. p. 296, PI. I.- 13 There is only one pair of simple salivary glands 

 V. XIII. {Tridactylus, Oedipoda, Gryllotalpa, with Tetyra, Pentatoma, Pyrrhocoris, Lygaeus, 

 Ephi]ipigera, Mantis, Blatta, Termes, and Naucoris, jVepa and Ranatra i two pairs with 

 Perla).* Coreus and Alydus. With Nepa and Ranatra, 



13 For the salivary organs of the Hemiptera, see, they dUate into an oval reservoir. 



beside Ramdohr, loc. cit. Taf. XXII. XXIII. 16 Syrtis, Reduvius, Pelegonus, and Corixa. 



especially L. Dufour, Recherch. sur les Hemi- 17 See L. Dufour, Ann. d. Sc. Nat. V. 1825, p. 



ptdres, p. 118, PI. I.-IX. 158, PI. IV. and Recherch. &c. PI. VIII. 



14 The two excretory ducts are of the same length 



* [ § 339, note 12.] See also Leidy, loc. cit. p. domen ; whUe the other two are about one-fourth 



62 (Spectrum femoratum). — Ed. as long. Beside these, on each side of the oesoph- 



t [ § 339, note 14.] With Belostoma, the agus, there is situated a sigmoid caecal pouch 



salivary glands are four In number, are of con- which opens by a narrow duct into the commence- 



glomerate structure and situated on each side of ment of the oesophagus in the vicinity of the termi- 



the oesophagus into the commencement of which nation of the salivary ducts ; these are perhaps 



they empty. Two of them are long and extend reservoirs of the saliva ; see Leidy, loc. cit. p. 63. 



backwards as far as the commencement of the ab- — Ed. 



