458 THE iNSECTA. <^§ 352, 353. 



moment of their escape from the vagina, and in this way the eggs are col- 

 lected in masses to be deposited in places fit for their incubation, ^'^ 



11. Male Ge?iital Organs. 



§ 



352. 



The Testicles, which are double like the ovaries, consist, sometimes of 

 two simple caeca, which are more or less long and torose, and sometimes 

 of many caeca, very variable as to their forms and disposition. Tlieir 

 mode of grouping resembles that of the ovaries ; indeed, their whole 

 appearance and contour, and the number and composition of their various 

 parts resemble remarkably those of the female organs. With many spe- 

 cies, these organs are covered by a lively-colored pigment layer, or envel- 

 oped by a special membrane {Tunica vaginalis). 



The two Vasa deferentia are of variable length, often exceeding that of 

 the -body, and therefore making several convolutions in the abdominal cav- 

 ity. When the testicles are composed of many caeca, there are often the 

 same number of these canals; but they often unite, on each side, into a 

 common duct. Sometimes they have, each, at their lower extremity, a 

 vesicular dilatation which may be regarded as a Vesicula semiyialis. At 

 their point of junction on the Ductus ejaculatorius, there are usually situ- 

 ated two, longer or shorter, simple Glandidae mucosae, which secrete a 

 quickly coagulating, granular mucus, which serves, during the copulatory 

 act, partly to fill and distend the Bursa copulatrix together with the 

 penis, and partly to surround portions of the sperm, and thereby form 

 spermatophores. '^' 



§ 353. 



The principal modifications observed with the internal male organs of 

 the Insecta, are the following. 



Among the Aptera, Lepisma is distinguished in having numerous oval, 

 testicular follicles, whose Vasa deferentia, after forming irregular ramifica- 

 tions, unite in two common excretory ducts, which, gradually enlarging, 

 terminate in a Ductus ejaculatorius at the point of insertion of two arcu- 

 ate accessory glands.*^' 



With the Hemiptera, the internal genital organs are of very variable 

 form.^'-' The Pentatomidae have only two simple, pyriform testicles, often 

 of a beautiful red color ; at their free extremity they sometimes have 

 several constrictions, and thus form the passage to the form proper to 

 many Geocorisae, which have seven long testicular tubes united in a fan-like 



i" The oviierous p-oove is short and triangular 1 For the various forms of the simple and com- 



with Libeilula vulgata and canceUata ; long, pound testicles, as well as for the male organs of the 



acuminate, and perpendicular with Cordulia me- Insecta in general, see Burmeister, Handb. &c. 



tai/ica ; long and cordately emarginate and closely I. p. 217, and Lacordazre, Introduct. &c. II. p. 



applied against the abdomen with Epitlieca bimac- 305. 



ulMa. A remarkable appendage, deeply exca- 1 See Treviranus, Verm. Schrift. II. p. 15, Taf. 



vated, situated to the exterior of the female genital IV. fig. 2. The Pediculidae have only two pairs 



organs of Doritis Apollo and mnemosyne, and of testicles. 



upon which, as yet, no Icpidopterist has given any a See L. Dufour, Rechereh. sur les Htmlpt. PI. 



details, is probably an ovigerous sac. X.-XIII. 



