on various Species of Hymenopterous Insects. 127 
perceived with the motions of the true Hymenopterous larve, 
which are more properly called vermiform. Looking, therefore, 
at the Hymenoptera, with reference only to the larvee, we should 
say that they are primarily divisible into two great groups; the 
first comprising the Tenthredinide and Uroceride, and the second 
all the other Hymenoptera, the passage being formed by the 
Uroceride. But let us not forget that the state of the larva is 
only preparatory to that future state of which Mr. MacLeay has 
himself remarked, that ‘ the true criterion of animal, as well as 
vegetable perfection, is the ability to continue the species ;”* and 
Messrs. Kirby and Spence give it as their opinion, that a striking 
agreement in the perfect state, which is the acme of their nature, 
affords a much more satisfactory reason for keeping two tribes 
together, than any difference observable in their larve or meta- 
morphosis for separating them.{ 
The pupa of this interesting insect decidedly belongs to the com- 
plete class of Metamorphosis in which the pupa is incomplete, being 
covered with a thin membraneous skin inclosing in separate and 
distinct sheaths the different organs of motion. Mr. Cooper found, 
on splitting a piece of the branch, several specimens in different 
stages of their pupa state (all, however, were dead) : some being 
of a light brown colour and shrivelled up as though they had died 
immediately on assuming this state, (Pl. X. fig. 15,) and without 
having their future parts so distinctly perceivable; others in an 
intermediate state; and some nearly ready to assume their last 
state, and in which all the parts of the future insect had acquired 
their natural colour and consistency, being only covered with the 
thin and now transparent skin of the pupa (P!. X. fig. 14). There 
were also several which had even become perfect insects found in 
the channels made by the larvae, but which were also dead. Iam 
not at all able to account for this circumstance, the larve being at 
the same time alive and healthy ; for we cannot suppose that nature 
would thus suffer any of her creatures intentionally to perish with- 
out having attained their perfect state, and performed the very 
purposes of their existence. How long the pupa state continues I 
know not, nor at what period of the year the perfect insect is 
developed, although they have been taken in the month of June. 
The pupa state is therefore exactly similar to that of all other 
Hymenoptera, and furnishes another proof that these insects ought 
not to be established into a distinct order as Mr. MacLeay pro- 
poses in his “ Horz Entomologice.” 
* Hore Entomologice, 446. 
+ Introduction to Entomology, vol. iv. p. 374. 
