330 



INSECTA. 



Fig. 168. 



no doubt, the semen accumulates, and which has been called by authors 

 the vesica seminalis. 



(877.) The canal (d) terminates by joining the corresponding duct from 

 the opposite side (d r ) to form a common tube (<?) ; but just at the point 

 of junction they are joined by two long auxiliary vessels (/,/), that have 

 been named sperm-vessels, gluten-vessels, and gum-vessels by different 

 authors, but which appear to be appropriated to the production of some 

 fluid, perhaps analogous to the prostatic fluid of mammalia, whereby the 

 bulk of the seminal liquor is increased in order to facilitate its expulsion. 

 Each of these auxiliary vessels consists of two parts a long and much- 

 convoluted portion (e e e), forming the secreting organ ; and a dilatation 

 (/), that must be looked upon as a reservoir for the fluid elaborated. 

 The common canal (g) receives all these secretions : it is at first enclosed 

 in a kind of sheath (7i), but, soon becoming muscular, it dilates into a 

 strong contractile canal (g, i), called the ductus ejaculatorius, which is 

 continued to the extremity of the penis. 



(878.) The intromittent organ itself is composed of two parts a pro- 

 trusible corneous tube (1 1), and an external horny sheath (n n), in which 

 the former is usually concealed and protected. 



(879.) Great variety, of course, is found in 

 the number, form, and general arrangement 

 of all the parts alluded to in the above de- 

 scription, when examined in different insects. 

 In the Hive-bee, for example, the testes 

 (fig. 168, a) are only two in number, and are 

 simple oval vesicles ; the vasa deferentla (b b) 

 are short, and the seminal receptacles (c) form 

 membranous sacculi. The auxiliary secreting 

 organs (d), although placed in the same posi- 

 tion as in Mdoloniha, are represented by 

 capacious caeca ; while the common excretory 

 duct (e) swells into a strong and muscular 

 bag (/), which constitutes the ejaculatory 

 apparatus. Still, however, it is easy to see 

 that, although diversified in appearance, the 

 parts here found are essentially similar to 

 those met with in the Cockchafer, and repre- 

 sent respectively the same organs. 



(880.) The female apparatus of repro- 

 duction presents a general correspondence, 

 both in form and arrangement, with the 

 sexual parts of the male insect. The ovaria 

 are simple secreting sacculi, or elongated 

 tubes, in which the germs or ova are pro- 

 duced instead of the seminal liquor ; and the excretory canals, or egg- 



Male generative organs of the 

 Hive Bee (Apis melllfica): 

 n, testes ; 6 6, vasa deferen- 

 tia; cc, seminal receptacles; 

 d, auxiliary glands ; e, common 

 excretory duct ;/, g, ejaculatory 

 sacculus. 



