376 ORDERS OF PTILOTA. 



flattened, and divided into two separated parts, forming 

 the backs of the two saws. In the ichneumons, these various 

 parts are so slender, that at first sight they appear to consist 

 but of a single piece : on more minutely examining the in- 

 strument, however, it will be found that it consists of a 

 scabbard, composed of two pieces, inclosing a fine hair-like 

 bristle, which is, in fact, the exact analogue of the stinging 

 part of the bee's sting, consisting of three pieces. 



These insects, which constitute the fifth Linnean order, 

 are unquestionably the most interesting of the insect tribes, 

 comprising as they do the bee, wasp, ant, sand-wasp, cuckoo- 

 flies, and saw-flies ; the economy of which is so remarkable, 

 that it has attracted the curiosity of the most uninquisitive 

 persons. Their colours are seldom brilliant ; brown, yellow, 

 black, or grey, being their prevailing tints ; neither do they 

 often acquire a large size, the majority being under an inch 



in length, and some being so exceedingly minute as to be 

 invisible to the naked eye, except when seen creeping against 



