186 
NATURAL HISTORY OR 
and living vegetation are frequently adorned with 
very beautiful and brilliant colours, but those that 
derive their nourishment from decomposed vegeta- 
bles are usually of a sombre hue. 
The larvae of these insects are long, soft, semicy- 
lindrical worms, divided into thirteen segments in- 
cluding the head, which is of a scaly texture, and pro- 
vided with powerful mandibles. The feet are six 
in number, and placed on the three segments im- 
mediately behind the head. Nine of the rings or 
segments have a conspicuous stigmatic opening, or 
air hole, on each side. The hinder portion of the 
body is much thicker than the other parts, and is 
usually curved inwards beneath the belly, even when 
the insect is in motion. Its movements are conse- 
quently slow and awkward, and the short scaly feet 
proving inadequate to support the equilibrium of 
the arched back, it frequently rolls over, or falls on 
one side. The general 
appearance of these grubs 
will be better understood 
from the annexed figure of 
that of the common Cock- 
chafer. Many of them live 
among excrementitious 
substances, or decomposed 
vegetables ; others consume the roots of plants, and 
often occasion very great injury to agricultural pro- 
duce. Before undergoing the metamorphosis by 
which they are converted into perfect beetles, the 
