OF INSECTS. 
165 
may without impropriety be noticed in this place. 
It consists of a reticulated web, of a white or yellow 
colour, the shreds of which, when examined by the 
microscope, are found to be constituted by small 
globules of animal matter. It is more or less com- 
pact in different insects, and even in the same insect 
according to its age, being loosest and most stringy 
in young individuals. It very nearly corresponds to 
the fat of the larger animals, but as chemical analysis 
has produced different results, its essential properties 
and uses cannot be considered always the same. 
Virtually, however, its uses may be regarded as two- 
fold ; first, to protect the various organs by forming 
a soft and elastic bed, which retains them in their 
place, and prevents them coming in too close con- 
tact with each other ; secondly, to afford a certain 
degree of nutriment when the insect is not in a con- 
dition to receive food. In the latter case, it exactly 
corresponds to the store of fat found in hybernating 
mammalia, when they go into their winter quarters. 
It is particularly plentiful in the caterpillars of the 
Lepidoptera ; as they go through their various meta- 
morphoses it gradually becomes more scanty, till it 
almost entirely disappears in the mature fly. It is 
hence naturally inferred that it supplies the requisite 
nutriment during the pupal sleep, and is gradually 
absorbed to aid in the development of the newly 
formed parts. Next to caterpillars it is most abund- 
ant in Coleoptera, Orthoptera, Hemiptera, and Neu- 
roptera ; or, speaking generally, it is more plenti- 
ful in masticating than sucking insects. Some dis- 
