222 FOOD OF INSECTS. 
by its pedicle to the beetle, each of the remainder being similarly connected 
with the one that precedes it; so that the nutriment drawn from the 
beetle passes to the last through the bodies and umbilical cords of the 
individuals which are intermediate.1 Some have regarded these bodies as 
true eggs ; and their analogy with the pedunculated eggs of Trombidium 
aquaticum, which also seem to derive nourishment from the water-boatmen, 
&c., to which they are fixed, and still more the circumstance of their ulti- 
mately losing their pedicle and detaching themselves from the infested 
beetles, give plausibility to the idea, Yet these animals are certainly fur- 
nished with feet, and have, according to De Geer?, a part resembling a 
mouth —characters which cannot be attributed to any egs. 
In the variety of their instruments of nutrition, which you must bear in 
mind are often quite different in the larva and perfect states, insects leave all 
other animals far behind. In common with them, a vast number (the orders 
Coleoptera, Hymenoptera, and Orthoptera, and the larve of Lepidoptera, 
some Diptera, &¢.) are furnished with jaws, but of very different construc- 
tions, and all admirably adapted for their intended services; some sharp, 
and armed with spines and branches for tearing flesh, others hooked for 
seizing, and at the same time hollow for suction; some calculated like 
shears for gnawing leaves, others more resembling grindstones, of a 
strength and solidity sufficient to’ reduce the hardest wood to powder: and 
this singularity attends the major part of these insects, that they possess 
in fact two pairs of jaws, an upper and an under pair, both placed horizon- 
tally, not vertically; the former apparently in most cases for the seizure 
and mastication of their prey; the latter, when hooked, for retaining and 
tearing, while the upper comminute it previously to its being swallowed. 
To the remainder of the class of insects, a mighty host, jaws would have 
been useless. Their refined liquid food requires instruments of a different 
construction, and with these they are profusely furnished. The innume- 
rable tribes of moths and butterflies eat nothing but the honey secreted in 
the nectaries of flowers, which are frequently situated at the bottom of a 
tube of great length. They are accordingly provided with an organ exqui- 
sitely fitted for its office—a slender tubular tongue, more or less long, 
sometimes not shorter than three inches, but spirally convoluted when at 
rest, like the mainspring of a watch, into a convenient compass. ‘This 
tongue, which they have the power of instantly unrolling, they dart into 
the bottom of a flower, and, as through a siphon, draw up a supply of the 
delicious nectar’on which they feed. A letter would scarcely suffice for 
describing fully the admirable structure of this organ. I must content my- 
self, therefore, with here briefly observing that it is of a cartilaginous 
substance, and apparently composed of a series of innumerable rings, 
which, to be capable of such rapid convolution, must be moved by an 
equal number of distinct muscles ; and that, though seemingly simple, it is 
in fact composed of three distinct tubes—the two lateral ones cylin- 
drical and entire, intended, as Reaumur thinks, for the reception of air, 
and the intermediate one, through which alone the honey is conveyed, 
nearly square, and formed of two separate grooves projecting from the 
lateral tubes; which grooves, by means of a most curious apparatus of 
hooks like those in the laminz of a feather, inosculate into each other, and 
1 De Geer, vii, 123, 3 Td, ibid, 126, 
