294 THE ESSEX NATURALIST.
of the Zygoptera, we notice that in the latter the eyes are rounded
and far apart ; the epicranium occupies the top and front of the
head.
The thorax of an insect consists of three parts, known as pro-
meso-and meta-thorax. In the dragonflies the prothorax is
very small, the meso-and meta-thorax have become united
into what is called the synthorax ; they have also become skewed
so that the legs are pushed forward and the wings backward.
Each segment of the thorax has a pair of legs, these are fairly
long, the front pair being the shortest ; their length is so arranged
that when folded forward the tarsi all reach to the mouth.
Their position close to the head makes them unfit for walking,
though quite suitable for climbing. Whilst flying, the legs are
sometimes used to form a trap, with which to capture their
prey. The abdomen consists of ten segments ; the last one carries
the anal appendages. In shape the abdomen is long compared
with its width ; the female body is generally stouter than that of
the male. In all the Zygoptera, and in many of the Anisoptera,
the female is provided with an ovipositor; this is situated on the
eighth and ninth segments and is composed of three paired
organs, these are called the anterior, median and lateral processes
The anterior and median processes are narrow, sharp pointed
blades, with teeth at their distal end forming a distinct saw. The
lateral processes, or valves as they are called, are broad and
leaf-like : at their end is a sharp pointed organ called the style,
which is often clothed with stiff bristles. In the male, the genital
pore opens mid ventrally on the ninth segment and is guarded
by two lateral flaps. The copulative apparatus is situated upon
the second and the anterior part of the third segment ; it consists
of a penis and a number of complicated accessory structures for
protecting the penis and for holding and guiding the ovipositor
of the female during copulation.
The courtship and copulation of dragonflies are very difficult
to observe, but I believe the following account to be generally
correct. The male when it emerges feeds for a time until it
becomes sexually matured, it then transfers the sperm from the
genital pore on the ninth segment to a chamber situated in
the penis. It then seeks out the female and couples with her in
the air, then the two fly to a bush or tree and copulation takes
place there. The male in many families remains coupled with the