450 



THE INSECTA. 



§349. 



ovaria'n tubes are, moreover, always enveloped by numerous tracliean net- 

 works.'^' Upon their length, which is very variable, depends the number 

 of the eggs or germs which are disposed in a single file ; and in this way, 

 they may be distinguished as uni-, bi- and multi-locular. The two Oviducts 

 are usually short and often dilated into a kind of calyx at their upper 

 extremity, if there are numerous ovarian tubes meeting at this point. 



The Seminal receptacle [Receptaculum seviinis) is a double or single, 

 solid capsule [Capsula semiiialis) of variable form and surrounded by a 

 muscuUir layer. It opens into the vagina below the point of junction of 

 the two oviducts, by means of a canal of variable length [Ductus semi- 

 ?ialis). This duct has sometimes a simple, or a bifurcated appendage 

 (Glandula appendicularis)/'^ The seminal receptacle never contains 

 spermatic particles with those females which have not rejected their pupa 

 covering, or especially with those still in a virgin state ; but after copula- 

 tion it always contains a multitude of these particles moving very actively, 

 and these movements are kept up for a long period, as may be observed 

 with those females which live over the winter.'^' 



The Copulatory pouch [Bursa copulatrix) consists nearly always, of a 

 «pacious, pyriform reservoir, which, with only a few exceptions, opens into 

 the vagina below the seminal receptacle. During copulation, it receive» 

 the penis, and often, also, the sperm which enters either by portions con- 

 tained in the spermatophores, or enveloped by a shapeless gelatinous 

 substance.'^' 



The secretory organs situated at the lower end of the vagina, consist, 

 usually, of two rather long, glandular tubes on each side of the vagina, 

 into which they open, either directly, or through two small special excre- 

 tory ducts. They often have, on their course, two vesiculiform reservoirs. 

 In most cases, these glandular organs appear to form a Sebaceous or 



and scattered through the cavity of the body be- 

 tween tlie fat-cells. The females are apodal, and 

 the ventral surface of their body, which resembles 

 that of the larvae, is occupied by a shallow canal 

 (Incubatory canal) wliich terminates caecally in 

 the penultimate segment of the body, and opens 

 upon the cephalothorax by a semilunar orifice 

 (Genital opening). From this canal jjass off into 

 the visceral cavity three to five forward-ljent tultes. 

 The eggs are developed in the visceral cavity, and 

 by these tubes the young larvae make their exit 

 therefrom ; see my Beitr. zur Naturgesch. d. wir- 

 bell. Thiere. p. 75, Taf. III. fig. 62, 67 ; and JVies;- 

 mann''s Arch. 1818, I. p. 147. Formerly, I erred 

 in taking the ventral for the dorsal surface with 

 these insects. 



^ J. MuUer has taken these filaments for vessels 

 communicating between the ovaries and the dorsal 

 vessel ; see Nov. Act. Nat. Cur. XII. p. 580. 



3 For a long time this Kereptaculum se.minis 

 remained wholly unobserved, or was taken for a 

 Bursa ciifiulatrix, or an organ secreting a viscous 

 substance for gluing the eggs together and to for- 

 eign objects. The older descriiitions and figures 

 give, therefore, only an imiierlect idea. It is only 

 lately that the constant presence and true nature 

 of this organ have bec^n recognized (see my memoir 

 in Mül(er\i Arch. 18;i7, p. Ö9-2, and Stein, Vergl. 

 Anat. &:c. 1S47, p. Uti). Yet, at this day, the cop- 

 ulatory pouch and seminal receptacle are fre(iuently 

 confouniled together -, and L. JJiifour, in i)articu- 

 lar, persists in his olil error in drsii;nating this sem- 

 inal receptacle as a Gl'iiule .iiilnjii/iie. 



■t See my observations mad'' np')n ye.upa {fVie^- 

 mann's Arch. 1S:3'J, 1. p. 107; and Culex (Ger- 



mar\<! Zeitsch. IX. 1840, p. 442). Stein, also (loc. 

 cit. p. 112), has shown that the spermatic particles 

 remain alive a long time in the seminal receptacles 

 of the Coleoptera. The liquid secreted by the 

 accessory gland serves, probably, to keep the 

 spermatic particles fresh, and to prevent them from 

 desiccation. The fecundation takes place undoubt- 

 edly when the eggs pass in front of the orifice of 

 the seminal recejftacle, which is then probably com- 

 pressed by an investing muscular apparatus. This 

 long preservation of sperm in the seminal receptacle 

 explains how the females of certain species can lay 

 eggs so long after copulation, and at a time wheu 

 the males have all di-iipinared. The time of the 

 full maturity of tli'- > --- iii tlie ovary, moreover, 

 does not always eoinihlr « iih that of the heat and 

 coijulation with the male. The observations wliich 

 have been made on this last point have been col. 

 lected by Müller (Nov. Act. Nat. Cur. XII. p. 624). 

 5 This copulatory pouch, which, from its large 

 size, was first perceived by entomologists, is even 

 now often taken for a fecundating sac, or a seminal 

 reservoir {Siicrmallicca). The spermatic particles 

 are carried, undoul)teclly by their own move- 

 ments, from this copulatory jxiuch into the Re 

 ce.ptaculum seminis ; and very probably they 

 begin to travel shortly after cojiulatiou, for, a lonjr 

 sojourn in the liurxa copulatrix does not ap- 

 ])ear advantageous, since those that remiiin over 

 become stiff and dead-like in the midst of the semi- 

 nal fluiil, which is granulous and viscid. J. Hun- 

 ter (I'hitos. Trans. 1774), in his experiments on 

 artificial fecundation, was successful only when he 

 took the sperm from the copulatory pouch of the 

 females which had jnst come from copulation. 



