588 



THE MICROSCOPE. 



extensor muscles are attached to both ungues and the 

 flaps ; the flaps, corrugated or arranged on the ridge and 

 furrow plan, are in some cases perfectly smooth on 

 their superior surface, in others this surface is covered 

 with minute scale-like hairs. The thickness of the flaps 

 on the Blow-fly does not exceed the 1 -2000th of an inch 

 at the margin ; thence they increase in thickness towards 

 the point of attachment. Projecting from their inferior 

 surface are the organs which have been termed ' hairs,' 

 1 hair-like appendages/ ' trumpet-shaped hairs,' &c. That 



these are the immediate 

 agents in holding is now 

 admitted by most obser- 

 vers, and it will be con- 

 venient to term them 

 '"tenent" hairs,' in allu- 

 sion to their office. Plate 

 VI. No. 140, the under 

 surface of left forefoot of 

 Musca Vomit-aria, is shown 

 with tenent-kairs ; a and b 

 are more magnified hairs, 

 a from below, b from the 

 side. 'No. 142 is the left 

 forefoot of Amara commu- 

 nis, showing under surface 



object natural size.) dages, one of which is seen 



more magnified at a. Nc. 143, under surface of left forefoot, 

 Ephydra riparia. This fly is met with sometimes in im- 

 mense numbers on the water in salt marshes ; it has no 

 power of climbing on glass, which is explained by the 

 structure of the tenent-hairs : the central tactile organ is 

 also very peculiar, the whole acting as a float, one to each 

 foot, to enable the fly to rest on the surface of the water ; a 

 is one of the external hairs. No. 135, under surface of left 

 1 'ivloot of Cassida viridis (Tortoise-beetle), showing the 

 bifurcate tenent appendages, one of which is given at a 

 inor< magn fled. These, in the ground-beetles, are met 

 with only in the males, and are used for sexual purposes,. 

 The delicacy of the structure of these hairs in the fly, the 



