320 MODERN CLASSIFICATION OF INSECTS. 
emarginate on the middle of the front edge, and the maxilla and 
labium are small, fleshy, and soldered together, the spinneret arising 
from the centre of the labium. The body of these larve is often 
naked, but more commonly more or less clothed with hairs, spines, or 
warts. Previous to assuming the pupa state, these caterpillars 
undergo a series of moultings, generally four in number. When full 
grown, they prepare for pupation, either by constructing cocoons 
entirely formed of silk, or mixed up with various additional ma- 
terials, or by securely affixing themselves in situations of safety ; 
some species simply suspending themselves by the tail, whilst other 
tribes ingeniously hold themselves up by fixing a cord across the 
middle of the body. ‘The details of these proceedings, as well as the 
various constructions of cocoons of different kinds, have been elabo- 
rately detailed by Réaumur in his Mémoires. Bonnet, also, has pub- 
lished many very interesting detached observations upon these sub- 
jects. The pup of these insects are different in their appearance, 
some being of a conical form, and others more or less angulated ; 
the former invariably producing moths, and the latter butterflies, 
being also naked ; the angular projections of their bodies not render- 
ing their situation inside a cocoon so commodious as the conical 
chrysalides. 
The chrysalis state of Lepidopterous insects is of that kind termed 
obtected ; the insect being incapable of eating or walking, with the 
limbs laid close upon the sides and breast, folded up under a hard 
skin, on which account they are much less distinctly perceptible than 
in other pupz, bearing, indeed, a great resemblance to an Egyptian 
mummy ; whence, Mr. Inwood, in a curious dissertation upon the 
Egyptian arts, has been led to consider that this and other designs 
had their origin in natural objects. 
The chrysalis, upon quitting the exuvia of the caterpillar, is soft 
and tender: by degrees, however, its external envelope becomes hard 
and friable ; the surface of the body is at first moistened with a viscid 
fluid, which exudes from beneath the wings and the other parts which 
are enclosed between these organs, and which becomes thickened, 
and hardens rapidly, and in so doing glues together the contiguous 
parts, which are consequently now enclosed in an additional envelope *; 
this taking place within twenty-four hours after the change, previous 
to which time it is easy to separate the various external organs of the 
* See my memoir on Eucheira socialis, as to the disposition of the limbs in the 
chrysalis. (Trans, Ent. Soe. vol. i.) 
