THE AUSTRALIAN NATURALIST. 97 
The egg-laying of the Dragonfly is different in different 
species, but there are two main groups. In one, the ovi- 
positor is large, in the other it is wanting altogether. The 
female of the former class pierces the tissue of water plants 
with its ovipositor and raises up the tissue, under which #. 
places the egg. As would be expected the egg is elongated 
and has a fairly sharp point at one end, which enables it to 
slip easily into the tissue of the plant. Sometimes the female 
puts her abdomen under the water, at other times both male 
and female will descend together, as much as three feet be- 
low the water. When seen under the water they have a 
silver-plated appearance, due to the envelope of air which 
they take down with them. When they descend, the wings 
are folded close to the body and reach nearly to its end, so 
that air is enclosed between them the whole way down. The 
hairs on the thorax also hold air between the head and thorax 
and thus the insect keeps perfectly dry. The other class lays 
eggs which are round in shape and are covered with sticky 
substance. The insect brushes its abdomen against the water 
while flying and washes off the eggs from it in small bundles. 
The sticky substance dissolves and the eggs are dispersed over 
the bottom of the water. No one knows how long the eggs 
take to hatch. The lecturer was of opinion that the time is 
six weeks. The eggs which he had under observation turned 
brown after the first week. Then two black spots appeared, 
these being the beady eyes of the larvae. At the end of six 
weeks they hatched out. They proved veritable cannibals, 
only ten being left out of fifty at the end of one day. Very 
few survive and the appetite of these is voracious. ‘The re- 
sult is that the skin soon tightens, and in common with other 
insects it is shed and a new one formed. How often it does 
this is not known. Those which the lecturer had under ob- 
servation were observed to change five times; but he could not 
say for certain that this was the total number of changes. 
Dragonfly larvae differ from all other known animals in 
having an enormous development of the underlip, which is in 
the form of a large jointed arm. In repose it covers the face, 
giving it a harmless and innocent expression. But as soon 
as its prey approaches near enough, this huge arm, furnished 
at its end with powerful teeth, it shot out, and the victim seiz- 
ed. The larva then worries it captive, shaking it from side to 
sidé until it is quiet, when it draws its underlip in and pro- 
ceeds to devour its food at leisure. 
We may divide the larvae roughly into two classes, mud- 
dwellers and stem-dwellers. Of the former there are three 
kinds. One kind buries itself in mud, allowing only its eyes 
and tail to show above water. Another kind simply sits at 
