PARTS OF INSECTS. 
35 
Ins U "i 1 °'j lS * n this part °f the leg, as we observe in Cerambyx, Gryl- 
of ’Ne 0t ^ ers : * n Libellula, Forjkula, fyc. three : in the anterior feet 
other^ U ° ■ ° ne ' *‘ be figure ot the tarsus is more variable than any 
to j.i P or t'on of the leg, and is in a most singular manner adapted 
surf 6 ln ®5 ct ' ,s m °de of life. The articulations in such as walk on die 
rol a ° e eartb are slender; those which burrow have them more 
Just. Many of those which inhabit waters have them flat and cili- 
h •' i at tbe ed S es - as hi the Hydrous. Others are furnished with 
Rist \ tufts or vascular flesh}- tubercles, which enable them to move 
* 1 SCCUI hy on smooth and slippery bodies in any direction ; an ad- 
nu able example presents itself in the common house-fly, which “ treads 
>e ceding, an inverted floor,” with the same facility that other insects 
" a k °n the surface of the ground. An occasional difference in the 
number and form of the joints of the tarsus is sometimes observed in 
the two sexes of the same species. The mot ion of each joint of the 
tarsus is performed in a single plane, and is directed by two muscles in 
each joint, one ol which is small and placed on the dorsal surface, the 
other larger and situated beneath. 
f xGuis, or Claw, the termination of the tarsus. In the greater 
number ot insects there are two claws attached to each tarsus; some 
a\ e on y one; and hi others furnished with two there Is an interme- 
ate process, forming by this means three. An appearance similar to 
this is seen in the legs of the Lucanm; hut this on minute examina- 
tion is found to be a distinct joint also, armed with a pair of claws pre- 
cisely resembling those which more obviously, from their size, appear 
define™ * m ' U ‘ S C0Ilslderalll y smaller, but is perfectl/well 
• 0r W " l £ s '■ * e 01 'g ans appropriated to flight. These arc 
°r four > and . are attached to the lateral part of the breast 
amonm mar § m of the thorax. They are placed to an equal 
Xth “u m 3 ® 0rre 1 s P° ndm g situation on botli sides of the insect, 
nished !' n 6 ""I CT b * tW ° or fimr ' Those insects which are fur- 
form " 1 >n * 011 ^ P aU wm gs have in these organs both an uni- 
differ t’no^ tnir J CC an , d Slze> Such as have two pair most frequently 
in shan ^ 1 >cln ^ ar £ cr those behind : there is also a difference 
markin’ , T y COIUmolll >' a considerable variation in the spots, 
hi all tf S ’ 3 • °™ er particulars, notwithstanding the prevailing hues 
Paler " lll S 3 ma J r h® tl>e same. In general the posterior pair is 
A k i t le n,ar ks obscure. 
by Dt i " v * uervures, (which are considered in the light of bones 
and are ’ * ho has ! named thcm Fterigotiia or' Wing-bones, 
in disposition iTn “ and diffe ™§ exceedingly 
branesconstii b r d between . two *•” and closely united mem- 
6tlt ute s the true wing in insects. This conformation is very 
c 1 
