718 EXTERNAL ANATOMY OF INSECTS. 



wards, and has an orifice in a channel at the end on each 

 side. Treviranus could not discover these orifices in the 

 sting of Scorpio europceus a ,• they may however be readily 

 seen if viewed with a sufficiently high power, though not 

 under a common pocket microscope. Whether the very 

 slender, many-jointed, real tail of the remarkable genus 

 Thelyphonus is used in any respect as a weapon, has 

 not been ascertained : it is a filiform hairy organ consist- 

 ing in some specimens of more than twenty joints, the 

 first being very much larger than the rest b . 



6. Appendages^. We are lastly to advert to those 

 appendages of the abdomen of which the use is not at 

 present discovered. These are the styles (styli) of the 

 Staphylinidce ; the leaflets (foliola) of the Libellulina ; 

 the floret (Jlosculus) of the Fulgora?; the cerci of the 

 Blattidce and Gryllina-, and the threads (Jila) of Ma- 

 chilis : but having nothing important to add concerning 

 them, the definitions of those terms will give you a suf- 

 ficiently clear idea of them d . As they are common to 

 both sexes, if their use is connected with the sexual in- 

 tercourse, it must be similar to that which Treviranus 

 ascribes to the pectens of scorpions, they must be in- 

 struments of excitement. 



And now, after this long discourse on the External 

 Anatomy and structure of these little beings, you may 

 think perhaps at first that the subject is exhausted ; and 



a Treviranus, ubisupr. 14. 



b In my specimen including the first joint there are twenty, and 

 some seem to have been broken off. In Roemer's figure (Genera, 

 t. xxix. /. ] 1.) there are only ten. Perhaps they vary in number ac- 

 cording to the age of the animal. 



e Plate XV. Fig. 13, 16, 17. d See above, p. 391 -. 



