14 THE STING. 
The knot is provided with a pair of spiracles, 
which are situated, as Forel states, in the front of the 
segment, and not behind, as supposed by Latreille. 
In most entomological works it is stated that the 
Myrmicide have a sting, and that, on the contrary, 
the Formicidz do not possess one. The latter family, 
indeed, possess a rudimentary structure representing 
the sting, but 1t seems merely to serve as a support for 
the poison duct. Dr. Dewitz, who has recently pub- 
lished! an interesting memoir on the subject, denies 
that the sting in Formicide is a reduced organ, and 
considers it rather as in an undeveloped condition, 
The ancestors of our existing Ants, in his opinion, 
had a large poison apparatus, with a chitinous support 
like that now present in Formica, from which the 
formidable weapons of the bees, wasps, and Myrmicide 
have been gradually developed. I confess that I am 
rather disposed, on the contrary, to regard the con- 
dition of the organ in Formica as a case of retrogres- 
sion contingent upon disuse. I find it difficult to 
suppose that organs—so complex, and yet so similar— 
as the stings of ants, bees, and wasps, should have 
been developed independently. 
Any opinion expressed by M. Dewitz on such a 
subject is, of course, entitled to much weight; never- 
theless there are some general considerations which 
seem to me conclusive against his view. If the sting 
» Zeit. f. wise. Zool., vol. xxviii. p. 627. 
