228 MODERN CLASSIFICATION OF INSECTS. 
the pupa, which is the proper view of the subject ; but as the wing- 
bearing segments of the pupa are necessarily increased in size, it fol- 
lows that they are also pushed backwards, so that the peduncular scale 
(f), instead of occupying the fourth segment of the larva, in effect 
occupies the fifth (exclusive of the head). It may, indeed, be as- 
serted, that as the body of the imago possesses two or three segments 
fewer than exist in the body of the larva, we may suppose that the 
loss of one of these segments takes place, at least, in this manner, and 
in this part of the body. This, however, can only be done by ad- 
mitting that the head and three thoracic segments of the imago are 
composed of five larva-segments, instead of four, an admission ne- 
gatived by all analogy with pedate larve; but Ratzeburg does not 
even imply this, because jig. 85. 5. is that of a male, as is proved, not 
only by the abdomen being 7-jointed, but also by the existence of the 
exserted male organs of generation. 
The larvze of those species of ants which are destitute of a sting 
enclose themselves ordinarily in an oval cocoon, of a dirty white co- 
lour (often mistaken for the eggs of the ants), marked at one end with 
a black spot, which corresponds with the hinder extremity of the body 
of the enclosed insect; this cocoon is composed of a very slender 
parchment-like envelope, formed of fine threads, spun by the larva, 
as Leuwenhoeck expressly describes; and is sufficiently delicate, 
when placed in spirits, to allow the limbs of the pupa to be seen 
through it (fig. 86.7. cocoon of ¢; fig. 86. 6. ditto of ? Formica 
fusca). The larve of those species which are furnished with a sting 
do not thus encase themselves in a cocoon, the pupa being entirely 
naked, and at first white, but afterwards assuming a darker colour. 
Formica fusca, our common small brown garden ant, has afforded me 
many opportunities of confirming Latreille’s curious statement, that 
sometimes the pupz are naked, and at others enclosed in a cocoon. 
The precise reason for this difference has still to be ascertained. The 
pupa exhibits all the organs of the imago, with the limbs laid along 
the breast ; those of the neuters being, of course, destitute of rudi- 
mental wings ( fig. 86. 8. pupa of Myrmica rubra $; jig. 86. 9. ditto 
? ). As the period draws nigh for the development of the imago, the 
workers gnaw ahole at one end of the cocoon, in order to form a pas- 
sage for the pupa; which, having its various limbs enclosed in sepa- 
rate but very delicate pellicles, possesses the power of moving them 
immediately previous to casting off this pellicle, and of making its 
escape out of the cocoon; immediately after which it disengages its 
