THE CANADIAN ENTOMOLOGIST. 203 
beautiful appearance when flying in the bright sunshine, and evidently 
suggested the popular names given to them by the French and Germans. 
The Dragon-fly is usually found in the vicinity of small streams or 
ponds, for reasons we will soon give. On bright and warm days in July 
and August it may be seen skimming over the surface of the water or 
ascending in graceful curves into the air, in search of food. When it 
. rests, its wings are expanded horizontally. 
Notwithstanding their graceful and ‘“ Demoiselle ” appearance, they 
are most bloodthirsty creatures. Their rapid flight and enormous range 
of vision enable them to capture other insects with ease, while, their taste 
not being limited, they can consume butterflies, moths and other insects 
without compunction, and they are known to destroy and eat each other, 
as well as very small fishes (Figuier). However, it is this ravenous 
propensity which makes this insect so very valuable to man, as they 
destroy immense numbers of other insects which are injurious to vegetable 
and other products, and do not injure these substances themselves. A 
few of them shut in a house will soon rid it of flies, bugs and mosquitoes, 
and therefore their presence should be welcomed. The popular opinion 
that they are dangerous to man is without foundation, as they can neither 
bite, sting, or poison him. 
We may now consider the development of Z. ¢rimaculata from the 
egg, as it furnishes some very curious and interesting information. 
When the female is about to deposit her eggs, she attaches herself to 
some plant growing out of the water, and pushing her abdomen beneath 
the surface, glues a bunch of eggs to the submerged stem or leaf (Uhler). 
These eggs produce larvee which have a distant and ugly resemblance to 
the perfect insect. The larva is active and passes its existence in the 
water, feeding on numerous weaker insects. It possesses a curious syringe 
like apparatus situated in the end of the body, by which it discharges a 
stream of water for a distance of two or three inches behind it, thereby 
propelling the insect forward. The motion thus given is most irregular 
and appears to be beyond the control of the larva. This curious arrange- 
ment serves for respiration as well as locomotion. 
The larva soon reaches the pupa state (corresponding to the chrysalis 
state of a butterfly), in which it is also active, crawling over the bottom 
of the stream preying on other insects. In this state it is longer than the 
