78 MODERN CLASSIFICATION OF INSECTS. 
sting as distinct instruments, and stating that there is a tribe which 
possesses both organs. (Hist. Nat. Hyménopt., p. 80.) I cannot but 
think, however, that there must be some mistake in this assertion, 
Burmeister has given another and apparently incorrect view of the 
analogous structure of this organ. (Manual of Entomol., p. 198.) 
Exceptions, of course, exist to almost all the characters of the order : 
thus, apterous insects are found in the families Formicidae, Mutillide, 
Chalcidide, Cynipide, &c. Some ants are destitute of mandibles ; 
others do not possess an aculeus ; and some do not appear to possess 
the least trace of organs of sight. 
The Hymenoptera undergo that species of metamorphosis which 
has been termed incomplete, the pupa itself being incomplete ; the 
larvee, in the majority, are vermiform and footless; the mouth in these 
is but slightly developed. In the saw-flies, however, the larvae resemble 
the caterpillars of Lepidoptera, having a scaly head and six scaly feet, 
and numerous fleshy prolegs, and the mouth is also strongly mandibu- 
lated; the mandibles, maxillze, and lips, being distinct and of a moderate 
size ; the extremity of the under lip is also furnished with a spinneret, 
for the discharge of the silken threads employed in the construction 
of the cocoon. The larve of the saw-flies feed upon leaves, and those 
of the Siricidee upon wood; but those of the remainder of the order 
being destitute of legs, are indebted to the instinctive care of the 
parent fly, which deposits her eggs in those situations where the future 
grubs will be certain of an ample supply of food, eitler in the interior 
of the bodies of other insects (as in the Ichneumons, &c.), or by feeding 
upon insects which have been captured and deposited with the eggs (as 
in the Fossores ), or by devouring the substance of vegetable galls raised 
by the irritating matter deposited by the female at the time of ovi- 
position (as in the Cynipida), or lastly, by feeding upon vegetable 
matter, as pollen paste, deposited with the egg, in curiously constructed 
nests, as in many bees. ‘The larvae of the ants, however, as well as of 
some species of bees, and other social species, are tended and fed by 
the perfect neuter insects, with as great care as though they were their 
own offspring. When arrived at their full growth, and after undergoing 
several previous moultings, these larve are transformed into inactive 
pup, in which all the limbs of the future insect are observable, 
encased in distinct sheaths, and folded upon the breast. In some 
small species of the order, chiefly belonging to the family Chalcidide, 
the limbs are so firmly arranged together, that the pupa has the appear- 
