436 MOTIONS OF INSECTS. 
(Hypera Rumicis) has twenty-four tubercular legs : but, what is remarkable, 
the six anterior ones, being longer than the rest, seem to represent the 
real legs, while the others represent the spurious ones, of lepidopterous 
farvee. These legs, however, are all fleshy tubercles, and have no claws, 
the place of which is supplied by slime, which covers all the underside of 
the body, and hinders the animal from falling. Another weevil (Livus 
paraplecticus) produces a grub inhabiting the water-hemlock, which has only 
six tubercles that occupy the place and are representatives of the legs of 
the perfect insect.? 
Some larvee have these tubercles armed with claws. The maggot of a 
fly described by De Geer (Volucella plumata) has six pair of them, each of 
which has three long claws, This animal has a radiated anus, and seems 
related to those flies that live in the nests of humble-bees. ° 
Insects, in the peculiarities of their structure, as we haye seen in many 
instances, sometimes realise the wildest fictions of the imagination. Should 
a trayeller tell you that he had seen a quadruped whose legs were on its 
back, you would immediately conclude that he was playing upon your 
credulity, and had lost all regard to truth. What then will you say to me, 
when I affirm, upon the evidence of two most unexceptionable witnesses, 
Reaumur and De Geer, that there are insects which exhibit this extra- 
ordinary structure? The grub of a little gall-fly, appearing to be Cynips 
Quercus inferus of Linné, which inhabits a ligneous gall resembling a berry 
to be met with on the underside of oak-leaves, was found by the former to 
have on its back, on the middle of each segment, a retractile fleshy pro- 
tuberance that resembled strikingly the spurious legs of some caterpillars, 
A little attention will convince any one, argues Reaumur, that the legs of 
insects circumstanced like the one under consideration, if it has any, 
should be on its back. For this grub, inhabiting a spherical cavity, in 
which it lies rolled up as it were in a ring, when it wants to move, will be 
enabled to do so, in this hollow sphere, with much more facility, by means 
of legs on the middle of its back, than if they were in their ordinary 
situation. So wisely has Providence ordered every thing. Another 
similar instance is recorded by De Geer, which indeed had been previously 
noticed, though cursorily, by the illustrious Frenchman.® There is a little 
larva, he observes, to be found at all seasons of the year, the depth of 
winter excepted, in stagnant waters, which keeps its body always doubled 
as it were in two, against the sides of ditches or the stalks of aquatic 
plants. If it is placed in a glass half full of water, it so fixes itself against 
the sides of it, that its head and tail are in the water while the remainder 
of the body is out of it; thus assuming the form of a siphon, the tail end 
being the longest. When this animal is disposed to feed, it lifts its head 
and places it horizontally on the surface of the water, so that it forms 4 
right angle with the rest of the body, which always remains in a situation 
perpendicular to the surface. It then agitates, with vivacity, a couple 0 
brushes, formed of hairs and fixed in the anterior part of the head, which, 
producing a current towards the mouth, it makes its meal of the various 
species of animalcula, abounding in stagnant waters, that come within the 
1 De Geer, v. 283. 2 Thid. v. 228. 
5 Ibid. vi. 187. t. viii. f. 8, 9. 4 Reaum. iii. 496. t, xlv. f. & 
5 Ibid. Mém, de V Acad, Roy, des Sciences de Paris An. 1714, p. 208, 
