426 MEANS OF DEFENCE OF INSECTS. 
some shelter themselves under an umbrella formed of their own excre. 
ment! You will exclaim, perhaps, that there is not a parallel case in all 
nature ;— it maybe so;—yet as Lam bound to confess the faults of insects 
as well as to extol their virtues, I must not conceal from you this op- 
probrium. Beetles of three different genera are given to this Hottentot 
habit. The first to which I shall introduce you is one that has long been 
celebrated under the name of the beetle of the lily (Crioceris merdigera, 
Cantaride de’ Gigh Vallisn.). The larvee of this insect have a very tender 
skin, which appears to require some covering from the impressions of the 
external air and from the rays of the sun ; and it finds nothing so well 
adapted to answer these purposes, and probably also to conceal itself from 
the birds, as its own excrement, with which it covers itself in the following 
manner. Its anus is remarkably situated, being on the back of the last 
segment of the body, and not at or under its extremity, as obtains in most 
insects. By means of such a position, the excrement when it issues from 
the body, instead of being pushed away and falling, is lifted up above the 
back in the direction of the head. When entirely clear of the passage, it 
falls, and is retained, though slightly, by its viscosity. The grub next, by 
a movement of its segments, conducts it from the place where it fell to the 
vicinity of the head. It effects this by swelling the segment on which the 
excrement is deposited, and contracting the following one, so that it ne- 
cessarily moves that way. Although, when discharged, it has a longitu- 
dinal direction, by the same action of the segments the animal contrives 
to place every grain transversely. Thus, when laid quite bare, it will 
cover itself in about two hours. There are often many layers of these 
grains upon the back of the insect, so as to form a coat of greater diameter 
than its body. When it becomes too heavy and stiff, it is thrown off, and 
a new one begun.'— The larva of the various species of the tortoise 
beetles (Cassida 1.) have all of them, as far as they are known, similar 
habits, and are furnished besides with a singular apparatus, by means of 
which they can elevate or drop their stercorarious parasol so as most ef- 
fectually to shelter or shade them. The instrument by which they effect 
this is an anal fork, upon which they deposit their excrement, and which 
in some is turned up and lies flat upon their backs; and in others forms 
different angles, from very acute to very obtuse, with their body ; and 
occasionally is unbent and in the same direction with it.2 In some species 
the excrement is not so disgusting as you may suppose, being formed into 
fine branching filaments. This is the case with C. maculata L.3 — In the 
cognate genus Imatidium, the larva also are merdigerous ; and that of J. 
Leayanum Latr., taken by Major-General Hardwicke in the East Indies, 
also produces an assemblage of very long filaments, that resemble a dried 
fucus or a filamentous lichen. ‘The clothing of the Tinee, clothes-moths, 
and others, and also of the case-worms, having enlarged upon in a former 
letter, I need not describe here, 
Some insects, that they may not be discovered and become the prey of 
their enemies when they are reposing, conceal themselves in flowers. ‘The 
male of a little bee (Heriades* Campanularum), a true Sybarite, dozes volup- 
tuously in the bells of the different species of Campanula — in which, in- 
1 Reaum. iii. 220, Compare Vallisnieri, Msperienz. ed Osservaz. 195. Ed. 1726. 
2 Reaum, 233. § Kirby in Lin, Trans, iii. 10. 
4 Apis. **. c. 2.7K 
