452 THE INSECTA. <§. 350. 



and many Geocorisae, tlie secretory apparatus consists of two round gland- 

 ular sacs/''^ while, with the Cicadidae, it is a single, long flexuous tube/^^ 

 The viviparous Aphididae differ from those which are oviparous, in that 

 their eight ovarian tubes are multilocular, and their oviducts entirely with- 

 out appendages ; while with the seciond or oviparous, these eight tubes are 

 unilocular, and there is a seminal receptacle and two sebaceous glands.'"' 



With tlie Diptera,*^"' the ovaries consist, usually, of numerous short, 

 three or four chambered tubes. With only a few species, these tubes are 

 long and have eighteen to twenty chambers.'"' The disposition of these 

 tubes varies considerably. With some, they are simply terminal to the 

 short oviduct ; while with others they form one or more series on the 

 sides of these organs, which, then, are longer. 



The Receptaculum seminis presents the most varied forms,''-' it is usu- 

 ally, triple, rarely simple or double,''"'' and is lined with a horny, brown 

 substance. It has a round, pyriform, or oblong shape, and, in this last 

 case, is often flexuous or spiral. The seminal ducts, which lead from 

 the receptacles to the vagina, are sometimes isolated, and sometimes united 

 into one or two common ducts before entering the vagina. Directly below 

 them on each side, are the points of junction of the two secretory organs, 

 which, always present with the Diptera, consist of two simple, rarely 

 ramose tubes, whose very small excretory ducts have, exceptionally only, a 

 vesiculiform dihxtation.''"" The Bursa copulatrix appears to be wanting with 

 all the Diptera. But, with many Muscidae, the vagina has, as a seminal 

 receptacle or uterus, a spacious, and sometimes two-lobed reservoir in which 

 the fecundated eoj^s are accumulated in great numbers, and remain until the 

 larvae are sufficiently developed to be hatched, making these animals vivi- 

 parous.''^' With certain species of Tachina, this uterus presents a remark- 

 able form ; the vagina is very long, spiral, and of equal size throughout ; 

 and, at certain periods, is crowded with larvae or small eggs.'"" With the 

 pupiparous Hippoboscidae, the female organs are formed on an entirely 

 special type, corresponding with the remarkable mode of the reproduction 



'i See L. Du/our, Recherch. loc. cit. PI. XIV. !■" The Receptaculum seminis is simple with 



XV. Pule-x, Empis, Dolichopus, and Hilara ; and 



8 See Meckel, Sue/cow, L. Dufour, Doyire, double with Piophila, Stomoxys and Borborus. 

 loc. cit. li See Siebold, a,nd Loew, \oc. cit. These glaiid- 



9 See my researches in Froriep^s neue Notiz. ular appendages secrete with certain Tipulidae a 

 XII. p. 307. Dutrochet (Ann. d. Sc. Nat. XXX. considerahle quantity of gelatinous substance which 

 1S33, p. 204, PI. XVII. C. fig. 1), it would appear, envelops the eggs and binds them in a kind of col- 

 has unwittingly figured the genital organs of an lar. These collars, which are deposited in the 

 oviparous Aphis, by taking the seminal receptacle water, have for a long time been figured by bot- 

 for a sperm-secreting organ. In this way he was anists among the algae under the name of Gloeo- 

 led to regard the viviparous Aphididae as her- nema. ' 



majjhrodites. 15 There are viviparous species in the genera 



10 For the internal female organs of the Diptera, Musca, Anthomyia, Sarcophasa, Tachina, 

 see L. Dufour, Ann. d. Sc. Nat. I. 1844, p. 253, Dexia, Mi/tog-ramma, &c. ; see my memoir in 

 and especially Loeiv, Horae anatom. p. 61. Froriep^s neue Notiz. III. p. 337, an<l iu fVieg- 



11 Ephydra and Tachina; see Loew, loc. cit. mann\i Arch. 1838, I. p. 197 ; also my Observat. 

 Taf. IV. tig. 3, 10. (luaed. Entom. &c. p. 18. L. Dufour (Ann. d. So. 



1^ For the Receptaculum seminis of the Dip- Nat. I. 1844, p. 261) has designated this reservoir 



tera,, see Siebold, in MuWer's Arch. 183^, p. 414, us Reservoir ovolarvigere ; see also his Ilist. d. 



Taf. XX. fig. 7-10 ; and especially Loew, loc. cit. Metamorph. et d. I'Anat. d. la Piophila petasionis. 



p. 89, Taf. IV.-VI., and in Gerjnar''s Zeitsch. III. Ibid. p. 382, PI. XVI. fig. 16, g. Loew (Horae 



p. 386, Taf. III.; the ifumerous figures of this anatom. Tab. IV. fig. 9, 11, 14, Tab. V. fig. 13) 



author will give some idea of the inexhaustible va- has figured analogous uteriform reservoirs with 



riety of forms of these organs. When L. Dufour Musca, Dexia, Piophila and Psila. 

 (Ann. d. Sc. Nat. 1. 1844, p. 262) would regard the W This long spiral-form vagina, which was for- 



seminal receptacle as a reservoir of the neighboring merly described as an ovarium spirale, is found in 



secretory organs, it is evident that this distinguished Tachina fera, tessellata, grossa, vulpina, hac- 



entomotomist must have entirely omitted a micro- wnrrlioidalis, &c.; see my memoir in H'leg- 



scopical analysis of the sulistanofs found in the mann's Arch. loc. cit. p. 194, and Reaumur, 



v.irious glands and other organs of lusecta. Mem. IV. 10 mem. p. 412, PI. X.VIX. fig. 7, 8. 



