462 THE INSECTA. ^ 354. 



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

 which ai'e 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 flesu- 

 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 diifer, in this respect, widely and constantly.*'-' 



Beside these proper copulatory organs, situated at the posterior 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, liymenoptera, 

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

 other external, which 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 



10 With the Carabidae, Hydrocanthari, and with they been well understood, the formation of many 



Mordella, Anthribus, Galeruca and CoccineUa. bad species might have been prevented. Th^ 



41 Melolontlia, Cetonia and Lucanu.i ; see L, prevent allied species from producing bastards by 

 Diifonr, Straus, and Suckow, loc. cit. adulterous connections, for the liarcl parts of the 



42 With the Staphylinidae, Cantharidae, Byrrhi- male correspond so exactly with those of the female, 

 dae, Ehiteridae, Tillidae, Meloidae, Tenebrionidae, that the organs of one species cannot fit those of 

 Pyrochroidae, Derraestidae, Cerambycidae, with another. L. Dufour has, therefore, i)roperly 

 Donacia, Helerocerus, &c. ; see L. Dufour, termed these copulatory organs as " la garantie 

 Suckow, loc. cit. and Brandt, Mediz. Zool. II. dc la conservation des types, et la sauvegarde 

 Taf. XVII. XI.K. This glandular apparatus is de la Ugitemite de respice." 



specially developed with Hydrophilus piceus, 3 This horny apparatus, from its large and often 



where, of the four pairs, one is distinguished for its tumid lateral valves is quite prominent with tlie 



length and thickness, and is composed at its extrem- Dolichopidae, Empidae, with Asilus, Lnphria, 



ity of numerous small follicles ; see Swammer- Ctcnopliora, Nemaiocera, and other Tipulid.ae. 



damm, Bib. der Nat. Taf. XXII. fig. 4 ; L. Da- See Schummel, Beitr. zur Entomol. Taf. I.-llI. 



four, loc. cit. VI. PI. VI. fig. 7, and Suckow, loc. (Tipula). 



cit. Taf. X. fig. 1, 3. ■* With the Panorpidae, these copulatory organs 



1 See Burmeister, Ilandb. &c. I. p. 227, Taf. are changed into very large pincers ; while with 



XIII. Psyche, the very long penis is protractile like tlii; 



^ As yet, these differences in form of the external tubes of a telescope, thus enabling these butterlliM 



male organs have been of little service to entomolo- to copulate with their females which remain cuu- 



gists in the distinclioti of species, although, had cealed in sacks. 



