48 MODERN CLASSIFICATION OF INSECTS. 
also attack each other, the conqueror in like manner sucking the body 
of the vanquished. The head is capable of very considerable movements, 
owing to the flexibility of the neck. During the summer, it does not 
require more than fifteen days for them to arrive at their full growth. 
They assume the pupa state immediately after finishing their cocoon, 
in which they remain, as inactive pups, during the winter. M. Audouin 
has informed me that the manner in which the imago makes its escape 
from its cocoon is not .by a head-piece scaling off, but by a slit at one 
end of the cocoon being continued in a spiral direction, forming a nar- 
rowed and elastic slip. See also Reaumur ((oe. cit.) ; Sowerby (British 
Miscellany, pl. 66. larva of Hemerobius —?); Haworth, in Ent. Trans., 
p- 62.; Disderi (in Zurin Trans., vol. iii.) ; Albin (pl. 64.) ; Goedart 
(No. 104.) ; De Geer (in Der Naturforscher, tom. iii. t. 3.). 
The perfect insect of Chrysopa perla has afforded to Mr. Bowerbank 
the subject of a valuable paper on the circulation of the blood of 
insects (Hntomol. Mag., vol. iv. p.178.; and see Tyrrell in Proceedings 
of Royal Society). 
M. Rambur has shown me specimens of two species of a new genus 
of this family, captured by him in Andalusia, in which the antenne are 
strongly bipectinated. 
Reaumur (Mém., tom. iil. pl. 32, 33.) has represented four different 
kinds of larva belonging to this family; but, unfortunately, it is im- 
possible to ascertain what are the species to which they respect- 
ively belong, with the exception of one, which is evidently that of 
Chrysopa perla. in one of these larve the sides of the segments 
are furnished with short bundles of hairs *, of which the others are 
destitute. One of these is naked, and of an elongated depressed 
form (like fig. 64. 8.) ; whilst another is equally naked, but much more 
convex, employing the extremity of the body as a seventh leg, and 
having the segments more continuous. The larva of Chrysopa perla 
is alsoconvex, but it covers itself with the carcasses of its victims, 
which gives it a most ludicrous appearance, and at the same time 
renders it almost invisible amongst lichens, &c. When full-fed these 
larvee inclose themselves in globular or oval cocoons of silk, spun 
from the spinneret, at the extremity of the body, and which in some 
species are exactly like open network. Compared with the perfect, 
insect, the small size of the cocoon and pupa appears extraordinary, 
* Frisch represents the larva of C. perla as furnished with fascicles (vol. i. st. 3. 
fig. 23, ). 
