EXTERNAL ANATOMY OF INSECTS. 717 



gans of oviposition I shall also describe hereafter, 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 tre- 

 mendous 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 poisonous 

 fangs of one tribe of the Ophidian reptiles 3 , the mandi- 

 bular of spiders b , the second pair of pedipalps, or the 

 fangs of the Scolopendrida , and the organ in question d ; 

 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 speaking is merely a 

 continuation of the abdomen, since the spinal marrow, the 

 intestinal canal, and the pseudocardia, are extended into it e . 

 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 se- 

 cond, perhaps, this formation favours the sublimation of 

 the venom, the long tail acting as an alembic for that 

 purpose. This machine consists of six angular joints in- 

 cluding the sting, the last but one being the longest, and 

 the last inflated, as it were, at the base, and terminating 

 in a sharp subulato-conical point which curves down- 



a Philos. Trans. 1818. t. xxii. 



b A r . Diet. d'Hist. Nat.'ii. 275—. Hoole's Leeuivenh. i. t. W.f. 19. T. 



Leeuwenh. Epist. 17- Octobr. 1687. / 10. C. 



d Hoole's Leeuwenh. i. t. v.f. 12, 13. e TYeviranus, Arach. 4. 



