MOTIONS OF INSECTS. 469 
clear, unless they have described it at different ages, when spiders often 
greatly change their appearance, that they mean the same species. ‘The 
former describes his as of the size of a small pin’s head, with its eight eyes 
disposed in a circle, having a black brown body and light yellow legs: while 
Dr. Strack represents his A. obtewtrix as more than two lines in length ; 
eyes four in a square, and two on each side touching each other ; thorax 
deep brown with paler streaks; abdomen below dull white, above dark 
copper brown, with a dentated white spot running longitudinally down the 
middle. The first of these, if distinct, as I suspect they are, agrees very 
well with the young of one which Lister observed as remarkable for taking 
aérial flights !, and which I have most usually seen so engaged. The other 
may possibly be that before noticed, which he found in such infinite num- 
bers in Cambridgeshire.* If this conjecture be correct, it will prove that 
the same species first produce the gossamer that covers the ground, and 
then, shooting other threads, mount upon them into the air. 
My last query was, What causes these webs ultimately to fall to the 
earth? Mr. White’s observation will, I think, furnish the best answer. 
“Tf the spiders have the power of coiling up their webs in the air, as 
Dr. Lister affirms, then when they become heavier than the air they will 
fall”’’ The more expanded the web the lighter and more buoyant, and 
the more condensed the heavier it must be. 
I trust you will allow, from this mass of evidence, that the Englisk 
Arachnologists— may 1 coin this term ?—were correct in their account of 
this singular phenomenon ; and think, with me, that Swammerdam (who, 
however, admits that spiders sail on their webs), and after him De Geer, 
were rather hasty when they stigmatised the discovery that these animals 
shoot their webs into the air, and so take flight, as a strange and unfounded 
opinion.* The fact, though so well authenticated, is indeed strange and 
wonderful, and affords another proof of the extraordinary powers, unpa 
ralleled in the higher orders of animals, with which the Creator has gifted 
the insect world. Were, indeed, man and the larger animals, with their 
present propensities, similarly endowed, the whole creation would soon go 
toruin. But these almost miraculous powers in the hands of these little 
beings only tend to keep it in order and beauty. Adorable is that Wis- 
dom, Power, and Goodness, that has distinguished these next to nothings 
by such peculiar endowments for our preservation as if given to the strong 
and mighty would work our destruction. 
After the foregoing marvellous detail of the aérial excursions of our in 
sect air-balloonists, I fear you will think the motions of those which fly by 
means of wings less interesting. You will find, however, that they are not 
altogether barren of amusement. Though the wings are the principal 
instruments of the flight of insects, yet there are others subsidiary to them, 
which J shall here enumerate, considering them more at large under the 
orders to which they severally belong. These are wing-cases (elytra. 
legmina, and hemelytra); winglets (alule); poisers (halteres); tailets 
(caudule) ; hooklets (hamuli) ; base-covers (tegule); &c. Besides, their 
tails, legs, and even antenne, assist them in some instances in this motion, 
As wings are common to almost the whole class, I shall consider their 
Structure here, Every wing consists of two membranes, more or less 
1 De Aranets, 66. ' @ Thid. 79, 5 Nat, Hist. i. 826. 
4 Swamm. Bibl. Wat, ed. Hill, i. 26. De Geer, vii. 190, 
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