a8o M ic r o s c o p ic a l E s s a y s .
and pupa {late, live in the water ; but when they have aflumed
their perfeft form, they are entirely terrellrial, and would be
drowned therein.
The notone&a, the nepa or aquatic fcorpion, &c. never quit
the water till they have paffed through all their transformations,
when they become amphibious, generally quitting it in the
evening.
The water-beetles, o f which there are many fpecies, remain in
the water all day, but towards evening come upon the ground
and fly about, but plunge themfelves again in the water at the
approach of the rifing fun. The larvte of tliefe infefts are entirely
aquatic; but when the time o f their pupa ftate arrives, they take
to the earth, where they make a fpherical cafe : fo that thefe infe
r s are aquatic as larva, terreftrial as pupa, and amphibious in
the imago ftate.
We find an inftance o f an infedl that lives at the fame time in
the water and the air, in the fingular larva defcribed by M. de
Reaumur, Memoires de l’Acad. in 1714, p. 203. It has the head
and tail in the water, while the reft of the body is continually
kept above the furface. In order to fupport itfelf in this fingular
pofition, it bends the body, bringing the head near the tail,
railing the reft above the water, and fupporting itfelf againft
fome fixed object, as' a plant, or againft the borders o f the pond ;
or, i f it is placed in a glafs veflel, againft the fides of the veflel;
and if the glafs be inclined gently, fo that the water may nearly
cover the larva, it immediately changes it’s pofition, in order that
part of the body may be kept dry.
At
At the baths o f Abano, a fma'U town in the Venetian ftate,
«here is a multitude o f fprings, ftrongly impregnated with fulphur,
•and of a boiling heat. In the midft of thefe boiling fprmgs,
within three 'feet, of four or five o f them, there is a tepid one
about blood-warm. Inthefe waters, not only the common pota-
mogeitous and confervas, or pond-weeds and water-moffes, are
found growing in-an healthy ftate ; but numbers o f fmall black
water-beetles -are feen fwimming about, which die on being taken
out and .plunged fuddenly ifito cold water*
Many infeëts that live under the furface o f the earth crawl-out
on certain occafions, as the julus, fcolopendra, and the onifcus -;
they are alfo often to be found under ftones, or pieces o f rotten
wood. Some infefts remain underground part of their life,butquit
that fituation after their-change ; as do fome caterpillars, many of
the coleoptrous clafs, &c. We have already taken nonce that
numbers delight to dwell in filth and naftmefs. The formica leo
forms it’s habitation in the fand, as well as many fpiders; -one o f
thefe forms a hole in-the fand, and then lines it with a kind of
filk, to prevent it’s crumbling-away ; it generally keeps on the
watch near the mouth o f the hole, and if it perceives a fly, runs
at dt with fuch velocity, asfeldom to fail in it’s attempt offeizing
it, -and then-carries it-to it’s little den.
Another fpider, ^Covered by Mr. l’Abbé Sauvage,+ burrows
in the earth like a rabbit, making a hole one or two feet deep, of
a regular diameter, and fufficiently large to move itfelf with eafe.
It lines the whole of it, either to keep the ground from tumbling
M m ln>
* Jones’s "Phyfiological Difquifitirins, p. ' l j u
Hiftoire de l’Acad. 1.758, p. 26,
If