716 EXTERNAL ANATOMY OF INSECTS. 
subject. The only remarkable one that is common to 
both sexes is that of the earwig, which is too well known 
to every child to call for any long description. The ex- 
ternal organs of oviposition I shall also describe here- 
after, and likewise those of secretion that have not already 
been noticed. 
5. Weapons. As the stings of some Hymenoptera are 
analogous to the ovipositors of the majority of that Order, 
I shall consider them both together when I treat of the 
sexual organs of insects; but there is one, and that a 
tremendous one, not connected with those organs, which 
may be noticed here. I mean the sting of the scorpion. 
There appears to be some analogy between the poison- 
ous fangs of one tribe of the Ophidian reptiles *, the 
mandibulze of spiders °, the second pair of pedipalps, or 
the fangs of the Scolopendride ‘, and the organ in ques- 
tion’; but the last possesses this peculiarity, that it is 
placed at the opposite extremity of the body, where it is 
preceded by a long jointed tail, which properly speak- 
ing is merely a continuation of the abdomen, since the 
spinal marrow, the intestinal canal, and the pseudocardia, 
are extended intoit*. Providence might have a double 
view in thus contracting the dimensions of this part of 
the abdomen; in the first place, the animal is by this 
enabled to turn its tail over its back preparatory to its 
inflicting a wound, and in the second, perhaps this for- 
mation favours the sublimation of the venom, the long 
4 Philos. Trans. 1818. t. Xxii. 
» N, Dict. d’ Hist. Nat. ii. 275 —. Hoole’s Leeuwenh. i. t.ti.f. 19.1 
© Leeuwenh. Eypist. 17. Octobr. 1687. f. 10. C. 
* Hoole’s Leeuwenh. 1. t. v. f. 12, 13. 
¢ Treviranus, Arach. 4. 
