080 



FEET OF INSECTS. 



whilst, when developed upon the Palpi and other organs in the 

 neighbourhood of the Mouth, it ministers to the sense of Taste* 



530. Feet. — Although the Feet of Insects are formed pretty 

 much on one general plan, yet that plan is subject to considerable 

 modifications, in accordance with the habits of life of different 

 species. The entire limb usually consists of five divisions, namely, 

 the Coxa or Hip, the Trochanter, the Femur or Thigh, the Tibia 

 or Shank, and the Tarsus or Foot ; and this last part is made up 

 of several successive joints. The typical number of these joints 

 seems to be Jive ; but that number is subject to reduction ; and the 

 vast order Coleoptera is subdivided into primary groups, accord- 

 ing as the Tarsus consists of Jive, four, or three segments. The 

 last joint of the Tarsus is usually furnished with a pair of strong 

 Hooks or Claws (Figs. 350, 351); and these are often serrated 

 (that is, furnished with saw-like teeth), especially near the base. 

 The under-surface of the other joints is frequently beset with tufts 

 of hairs, which are arranged in various modes, sometimes forming 

 a complete ' Sole ; ' this is especially the case in the Family Cur- 

 culionidce ; so that a pair of the feet of the Diamond-Beetle, 

 mounted so that one shows the upper surface made resplendent by 



its .jewel - like 

 scales, and the 

 other the hairy 

 cushion beneath, 

 is a very in- 

 teresting object. 

 In many Insects, 

 especially of the 

 Fly kind, the 

 Foot is furnished 

 with a pair of 

 membranous ex- 

 pansions termed 

 Pidvilli (Fig. 

 350); and these 

 are beset with 

 numerous Hairs, 

 each of which 

 has a minute 

 disk at its ex- 

 tremity. This 

 structure is evi- 

 dently connected with the power which these Insects possess of 



Fig. 350. 



Foot of Fly. 



* See his Memoir 'On a new Organ in Insects,' in " Journal of Lin- 

 nsean Society," Vol. i. (1856 , p. 136 ; his 'Further remarks on the Organs 

 found on the bases of the Halteres and Wings of Insects,' in " Transact, 

 of the Linn. Soc," Vol. xxii., p. 141 ; and his Memoir ' On certain Sensory 

 Organs in Insects hitherto undescribed,' in " Transact, of Linn. Soc," 

 Vol. xxiii., p. 189. 



