420 THE INSECTA. <§, 337. 



is, attached to the under lip, a peculiar prehensile organ which covers, like 

 a mask, the masticatory organs, and, by means of a double articulation, can 

 be let down and then returned with the utmost quickness. During this 

 manoeuvre, the prey is seized by two acute hooks inserted on the anterior 

 border of this lip, and carried to the mouth.*-' 



The parts of the mouth of the Insecta may be divided into Masticatory 

 and Suctorial organs, between which, however, there are many intermediate 

 forms. The second are, properly speaking, modifications of the first, and 

 for this reason, the last should be described first ; the special details of 

 these organs, however, belong to the domain of Zoology. 



These masticatory organs *'"' consist of a pair of Mandibles and a pair of 

 Maxillae, which move laterally and are more or less covered by an upper 

 [Labrum), and an under [Labium) lip. The upper jaws [Mandibulae) 

 exceed in hardness all the other parts of the masticatory apparatus, and 

 consist of two simple, horny organs, often denticulated at their extremity. 

 The under jaws [Maxillae) are, usually, softer, and composed of several 

 pieces, — of which the most essential are : Palpi m.axillares, composed of 

 from one to six articles, and directed outwards ; and the stipule, usually 

 denticulated or ciliated, and divided into a Lobus extermis and iiiternus. The 

 under lip, which supports two Palpi labiales composed of from one to four 

 articles, may thus be considered as another pair of maxillae the lateral 

 halves of which are more or less fused together on the median line.*** 

 Such are the oral organs with the Coleoptera, the Neuroptera, and the 

 Orthoptera. It is interesting to remark that the Orthoptera, in the widest 

 accej^tation of the term, have in common, this character, that their under 

 lip is divided by a deep fissure into lateral halves, while that of the Neu- 

 roptera and Coleoptera consists of a single piece.'"'' 



At the base of the under lip is attached the tongue, which, either fleshy 

 or horny, is single or cleft. Often it is completely abortive, but in other 

 cases, on the contrary, it is very long and changed into a suctorial organ. 

 This last form is most prominent with the Hymenoptera, where the two 

 jaws have, at the same time, ceased to be masticatory organs, and form a 

 sheath enveloping the tongue and labial palpi.'''* 



The oral parts are changed into suctorial organs with the Diptera, 

 Hemiptera, and Lepidoptera. The first have a Proboscis, formed by the under 

 lip transformed into a suctorial tube [Theca) which is often geniculate. 

 At its base are from four to six bristles which may be regarded, some as 

 maxillae and mandibles, and others as representing the tongue.'"' With 



2 See Roesel, Insektenbelustigungen, II. Insec- holometabolic Neuroptera. This justifies the sepa- 

 torum aquatil. Classis II. p. 12, Taf. III. IX., and ration we have made of the first whose pupae take 

 Siickotv, in Heusinger''s Zeitsch. d. organ. Physik. food and are active, from the second whose pupae 

 II. Taf. I. are inactive and do not eat. We have placed these 



3 Beside the so often cited writings of Straim, last among the Orthoptera, because, like them, they 

 Kirby and Spence, Brandt and Ratzehiirg-, Bur- have in all their states a bifid under lip. The dif- 

 meister, Lacordaire, Newport, and ifestwood, ferences between the under lip of the Orthoptera 

 see Savif^ny, Mem. sur les anim. sans vert^bres, I. and that of the Neuroptera are well shown in Savig- 

 p. 1, PI. I.-IV.; also, Isis, 1818, p. 1405, Taf. XVIII. ny''s excellent figures of the buccal organs of these 

 Nees von Esenbeck, Isis, 1818, p. 1386, and Insects (Descript. d. I'Egypte, Orthopteres, PI. I.- 

 Suckow, in Heusinger's Zeitsch. &c. III. Taf. I.-IX. VII. and Neuropt^res, PI. I.-III. 



4 This opinion, before advanced by Oken, Savig-- C See Swammerdamrn, Bib. der Nat. Taf. XVII. 

 ny, and Lench, has been sustained with very many fig. 5 ; Treviranus, Verm. Schrlft. II. lift. 2, p. 

 details by Bralle (Ann. d; Sc. Nat. 11. 1844. p. 324). 112, Taf. XII.-XIV. ; Brandt and Ratzeburg, 



!> On account of these modifications of the under Mediz. Zool. II. Taf. XXV. tig. 8-16 ; Newport, 



Up, to which Erichson (Entomograph. lift. 1, ]>. Cyclop, loc. cit. p. 897, fig. 375, 376 ; but especially 



5, and in Germar^s Zeitsch. I. p. 150, Taf. II.) has Savisny, Descript. de I'Egypte, Hymenopteres, PI. 



especially called the attention, we can distinguish, I.-XX. 



ill their perfect state, the hemimetabolic from the 7 gee Savigny, JItni. sur les anim. sans vert6- 



