Gi]NERAtlVE ORGANS. 81 



by SmyntJmriLS are situated in the Lead, at tlie place 

 where it is attached to the body. 



As regards the other species, I differ still more from 

 MM. Nicolet and Von Olfers. Having examined Tomo- 

 cerus phmibeus, as well as species of Aclwrutes, Lepido- 

 cyrtus, Isotoma, and Lipura, I am satisfied that they do 

 not possess any tracheal system answering to the 

 descriptions either of Mcolet or of Von Olfers. 



The generative organs (PI. LXII, figs. 10, 11) are 

 very simple, and similar in the two sexes ; the testes and 

 ovaries consisting of single tubes one on each side of 

 the body. They commence near the anterior part of 

 the abdomen, and posteriorly unite to form a vas de- 

 ferens, which opens, on the ventral surface, imme- 

 diately behind the base of the saltatory appendage. In 

 the globular species the case is somewhat different. 

 Owing to the delicacy of their membranous envelope, it 

 is not easy to extract the ovary entire, but the best way 

 is to make a section of the animal from the back, at 

 the anterior part of the thorax, to the base of the 

 spring ; in this case the ovaries will generally be found 

 uninjured, and may be separated from the other organs 

 without very much difficulty. They consist of a single, 

 short, and broad egg-tube on each side, and unite 

 posteriorly to form a narrow vagina about '003125" in 

 length. Having found it impossible to remove the 

 skin in such a manner as to expose the ovaries in sitil, 

 and as the method above described destroys, of course, 

 the natural position of the organs, I am unable to say 

 much as to the usual position of the ovaries. They 

 did not appear, however, to pass directly forwards, but 

 seemed rather to curve round from the point of attach- 

 ment to the vagina, so as to lie rather in the posterior 

 part of the body. 



M. Nicolet was unsuccessful in his search for the 

 organs of generation. " Je I'ai deja dit," he says, 

 " les difficultes q-ue 1' extreme petitesse de ces insectes 

 oppose a la dissection, rendent fort difficile 1' etude de 

 leur organisation interieure, qui peut-etre restera encore 



6 



