396 The Feet of Insects. 



the running of a man at the rate of twenty miles a minute. 

 How astonishing, then, are the powers concealed within this 

 tiny foot ! 



Nor is it the last joint of the tarsi only that accomplishes 

 this feat ; the flexor and extensor muscles, which are external 

 to the bone in the claw of a cat, here lie within the crust of an 

 insect's leg, and with their attendant nerves, and the life-giving 

 circulation of vital fluid, attain their full development in the 

 thickness of the femur, or thigh. Even as in the human arm 

 or leg the fulness of elastic fibre denotes a strong-limbed man, 

 so the shape of an insect's leg will give a pretty correct idea of 

 its habits of leaping, or walking, or running; as, for instance, 

 the remarkably fast fly, Btenopterijx Hirundinis, which infests. 

 our poor house-swallow. How robust are its thighs, and how 

 strong are the toothed claws — no wonder it springs so deftly 

 through, and clings so tightly to the downy feathers of the 

 young bird. Beside this leg I have drawn one of the Tipulee — 

 long and slender, with small foot and hooked claw, such as is 

 best adapted for an insect whose life is on the wing, or who only 

 stalks along the grass to deposit its eggs. Observe, also, that 

 the Stenopter} T x has no large pulvillus ; they would greatly im- 

 pede this fly in its movements, therefore they are extremely 

 small. Compare them with the long, large lobes of the house- 

 fly, or Asilus, which have the habit of resting on walls or stems 

 of trees (fig. 2) ; or with the foot of a Lejptis — a pretty quiet fly, 

 fond of repose in the sunshine of summer, where it is easily 

 taken on the bark of forest trees; it has three lobes in each 

 pulvillus, and by no means muscular legs (fig. 3). 



The claws of Diptera have many modifications as well as 

 the pulvillus. In the month of July, seeing our pony tor- 

 mented by a very pretty little piebald fly (Simulium elegans) 

 waving its white-banded fore-legs in an ecstasy of enjoyment as 

 it refreshed itself with the warm blood of our " Black Prince/' 

 I caught one, and observed its variegated tibia, and that its 

 claws were toothed with a small pulvillus, probably for running 

 quickly over the horse and clinging to the hair (fig. 4). 



Most of the Tipulse, or gnat tribe, have toothed claws ; they 

 hang upon leaves, they rest upon grass and fern, and cling to 

 water-plants or floating fragments on the water whenever they 

 are commanded to deposit their eggs. The claw of the midge 

 {Ceratopogon) is remarkably toothed and curved (figs. 10, 14, 

 and 15). This is not the window midge {Psycho da), which 

 requires, and has, a larger pulvillus and thicker legs for the 

 hopping they indulge in, always zigzag, too, from right to left 

 and left to right up the window pane. 



The Ceraiopogon are those beautiful but most annoying 

 little gnats who dance in merry companies by river sides and on 



