462 



THE INSECTA. 



^354. 



ular apparatus consists of only two simple, longer or shorter caeca/^^ 

 which are sometimes quite long and torose.'^'' Another series of Coleop- 

 tera have four to eight caecal appendages, disposed in pairs, and variable 

 as to length and volume. One of these pairs is probably only a reservoir 

 for the secreted product of the others. <■•-' The Ductus ejaculatorius is 

 always very muscular, and with very many species, quite long and flexu- 

 ous, and the penis therefore can be widely protruded during copulation. 



§ 354. 



The Copulatory organs of the male Insecta are valve-like or forficulate, 

 horny appendages,'" which are so variable in their form that the most 

 allied species diti'er, in this respect, widely and constantly. ^-^ 



Beside these proper copulatory organs, situated at the jjosterior extremity 

 of the abdomen, there are often on the antennae, the parts of the mouth, 

 the legs and other regions of the body, auxiliary organs used for seizing 

 and retaining the female, and which have long been objects 'of careful 

 description in zoology. 



With most Hemiptera, the posterior extremity of the abdomen conceals 

 a horny capsule which contains a protractile, tubular penis. With very 

 many Diptera, the copulatory organs project prominently in the same 

 region of the body, and consist often of two horny valves of diflerent forms 

 which envelop a rather long penis.*''' The Lepidoptera, Hymenoptera, 

 Orthoptera, and Neuroptera, have two pairs of valves, one internal, the 

 other external, Avhich enclose a tubular or groove-like penis.''*' 



The Ephemeridae and the Strepsiptera, only, are distinguished by their 

 very simple copulatory organs ; for with the first there is only a simple 

 penis without a valvular apparatus. This last is replaced by two long, 

 small, triarticulated stylets, situated on the penultimate abdominal seg- 

 ment and curved inwardly ; while with the Strepsiptera, the penis, also 

 naked and horny, is so articulated that it can be applied laterally against 

 the abdomen, like the blade of a knife in its handle. 



With the Libellulidae, however, the orifice of the Ductus ejaculatorius is 

 most simple, being covered only by two very small oval valves. But the 

 penis is not wanting with these Insecta ; it is singularly concealed, together 

 with a horny-walled seminal vesicle, in a fossa situated at the base of the 



4<» With the Carabidae, Hydrocanthari, and with 

 Mordel/n, Anthribus, Galeruca and Coccinella. 



41 Melulontha, Cetonia and Lucanus ; see £,. 

 Diifoiir, Straus, and Suckow, loc. cit. 



■ti With tliL' StP|)liylinidae, Canthariiiae, Byrrhi- 

 dae, Elatt'i'idae, Tillidae, Meloidae, Tenebrionidae, 

 Pyrocln-oidae, Dermeslidae, Cerambycidae, with 

 Do7iacia, Heterocerus, &c. ; see L. Dufour, 

 Suckow, loc. cit. and Brandt, Mediz. /ool. II. 

 Taf. XVII. XIX. Tiiis glandular apparatus is 

 specially developed with Hijdrophitus piceus, 

 where, of the four pairs, oTie is distinguished for its 

 length and thickness, and is composed at its extrem- 

 ity of numerous small follicles ; see Sivammer- 

 damm, Bib. der Nat. Taf. XXII. fig. 4 ; L. Dii- 

 four, loc. cit. VI. i'l. \l. fig. 7, and Suckow, loc. 

 cit. Taf. X. fig. 1, 3. 



1 See Burmeister, Haudb. &c. I. p. 227, Taf. 

 XIII. 



2 As yet, these differences in form of the external 

 male organs have bfrn of little service to entomolo- 

 gists in the distinction of species, although, had 



they been well understood, the formation of many 

 bad species might have been prevented. They 

 prevent allied species from producing bastards by 

 adulterous connections, for the hard parts of the 

 male corresjiond so exactly with those of the female, 

 that the organs of one species cannot fit those of 

 another. L. Dufour lias, therefore, jirojierly 

 termed these copulatory organs as "/a ^arantie 

 de In conservation de.s types, et la sauvci^arde 

 de In legitctnite de respece.'" 



'■'' This horny apparatus, from its large and often 

 tumid lateral valves is quite proniinent with the 

 Dolichopidae, Jlmpidae, with Asilus, Laphria, 

 Ctenophora, Nematoccra, and other Tiinilidae. 

 See Schummel, Beitr. zur Entomol. Taf. I.-III. 

 (Tipuin). 



i With the Panorpidae, these copulatory organs 

 are changed into very large pincers ; while with 

 Psyche, the very long penis is protractile liUe the 

 tubes of a telescope, thus cnaliling these buitertjies 

 to copulate with their females which remain con- 

 cealed in sacks. 



