HYMENOPTERA — FORMICIDE. 227 
body of the larva. My figures 86. 4. and 5. are copied from Dr. 
Ratzeburg’s memoir, and represent the larva at different stages, but 
near to the period of assuming the pupa state. In fig. 86.4. the eye will 
be seen at the back of the first segment (b) of the body ; the antennz 
(ant.) occupying part of this segment, but extending into the head 
(a); the fore wings (w. 1.) will be observed in the second segment of 
the body (c): the hind wings on the third segment (d); whilst the 
fourth and fifth segments (e and f) will be seen to be considerably 
constricted. In jig. 86. 5. the head (h), antenne (ant.), and eyes of 
the pupa, are seen to be entirely withdrawn from the head of the larva, 
and to occupy the first segment; and as the peduncle is still more 
decidedly seen to occupy the fifth segment (f), it follows that the 
collar (t. 1.), mesothoracic scutum (t. 2.), and scutellum (t. 3.), and 
the metathoracic preescutum (t. 4.), and scutellum (e), must be the 
three intermediate segments. Without intending to express any 
doubt as to the correctness of Dr. Ratzeburg’s actual observations, I 
cannot admit the theory by which he endeavours to account for the 
appearances he has described. As already noticed, in p. 79., the 
necessarily increased size of the head of the imago*, requisite for the 
support of organs to be employed by an insect in searching for its own 
food (whereas in the larva state there was no need of highly de- 
veloped trophi, the insect being fed by others, and that merely with 
a thickened liquid), together, also, with the equally necessarily in- 
creased size of the mesothorax requisite for the support of the large 
pair of fore wings, and the consequent decrease in size of the pro- 
thorax and its collar, must equally necessitate a diversity of size in the 
segments of the pupa (although still invested in the larva skin) ; hence 
we find the head so much increased in size, that it is pushed back so 
as also to occupy the first seginent of the larva ; the prothorax (t.1.), on 
the other hand, is so reduced in size, that it cannot be said to occupy a 
segment of itself; so that we may either consider it as forming part of 
the first segment with the head, in which case no anomaly will exist, 
the head and prothorax of the pupa occupying the head and first 
segment of the larva, or we may regard it as part only of the second 
segment, the remainder being occupied by part of the mesothorax of 
* Tam happy to learn from the most able entomotomist our country has yet 
produced, G. Newport, Esq., that my view of this subject is fully confirmed by 
the nervous system of the animal at the period of its undergoing these changes, in 
_ his forthcoming article, “ Insect,” in the Cyclop, of Anatomy. ; 
QZ 
