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 

 Myrmicidse have a sting, and that, on the contrary, 

 the Formicidse do not possess one. The latter family, 

 indeed, possess a rudimentary structm'e representing 

 the sting, but it 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 Formicidas is a reduced organ, and 

 ■considers it rather as in an undeveloped condition. 

 The ancestors of our existing Ants, in his opinion, 

 liad a large poison apparatus, with a chitinous support 

 like that now present in Formica, from which the 

 formidable weapons of the bees, wasps, and Myrmicidag 

 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. ivhs. Zool., vol. xxviii. p. 527. 



