INSECTS: THEIR MOUTHS 17L 



by the insect, and will sometimes open when under exami- 

 nation; but no instrument that I can apply to them is suffi- 

 ciently delicate to effect their separation at my pleasure. 

 Just at the very tip, however, under this high power, we 

 can see, by the semi -transparency of the amber-colored 

 chitine of which the organ is composed, that there is an- 

 other tip a little shorter, and as it were contained within 

 the other. This inner point is cut along its edges into 

 saw teeth pointing backward. Such exquisite mechanism 

 is bestowed upon the structure, and such elaborate con- 

 trivance is displayed for the comfort of an obscure and 

 obscene insect, by Him who has not disdained to exercise 

 his skill and wisdom in its creation! 



You know the stout flies which are denominated Horse- 

 flies or Whame- flies (Tabanus), which are so numerous in 

 the latter part of summer, flying around horses, and men 

 too, if we intrude upon their domains. They are contin- 

 ually alighting on the objects of their attentions, and 

 though driven away, returning with annoying pertinacity 

 to the attack. You may always recognize them by the 

 brilliant metallic hues reds, yellows, and greens with 

 which their large eyes are painted, often in stripes or 

 bands. These are voracious blood-suckers; and, as might 

 be supposed from their propensities, they are well fur- 

 nished with lancets for their surgery. Here you may see 

 their case of instruments, which are so effective, Keau- 

 mur tells us, that having compelled one to disgorge the 

 blood it had swallowed, the quantity appeared to him 

 greater than the whole body of the insect could have been 

 supposed capable of containing. 



All the parts here are formed of the common amber- 

 colored chitine, brilliantly clear and translucent. The up- 



