LETTERS ON ENTOMOLOGY. 121 
membranes, will be modulated and augmented 
by them. What can be more complex and ad- 
mirable than all this apparatus ? We know not 
how many wonders are contained in the ap- 
parently insignificant beings we tread under foot 
every day, without even seeing them. 
The common dragon-fly, or Libellula varia, is 
a very beautiful insect, and is generally found 
near water ; it has a very large head, with con- 
spicuous eyes, large transparent wings, with 
black veins, and a very long body richly varie- 
gated with blue and black. It is of a very ra- 
pacious nature, and preys on the smaller insects, 
but is perfectly destitute of a sting. It proceeds 
from a larva which inhabits the water, and is of 
a very peculiar and disagreeable form. During 
this state, which lasts two years, it is as rapacious 
as when perfect. When the period of its change 
is arrived, it ascends the stem of some water- 
plant, and by a few efforts breaks open the skin 
of the back, when the inclosed dragon-fly gra- 
dually emerges ; its wings, which are at first 
very short, tender, and contracted, expanding by 
degrees to their full size. In the space of about 
half an hour the change is complete ; and the 
same animal which before that time would have 
been killed by any long exposure to the air, would 
G 
