53 



back — for it is wofully round-shouldered — while its long, thin legs, shrunken as if from 

 disease, are drawn up beneath its breast, and what a hobgoblin it is ! 



" Its gleaming wings are, however, beautiful objects. They form a broad expanse of 

 delicate parchment-like membrane drawn over an intricate network of veins. Though the 

 body i.s bulky, it is light, and easily sustained by the wings. The long-tail undoubtedly acts 

 as a rudder to steady its flight." 



While we do not hold the Dragon fly to be the " very incarnation of ugliness and the 

 perfection of all that is hideous," as does the author above-named wc do not believe its bene- 

 fits to man have been exaggerated. The rapid flight and enormous range of vision of these 

 creatures enable them to capture other insects with ease ; while, their taste not being limited, 

 they destroy moths, butterflies, and other insects without compunction, and they have been 

 known to destroy and eat each other as well as very small fishes. However, it is this rave- 

 nous j)ropensity which makes this insect so valuable to man, as they destroy immense numbers 

 of other insects which are injurious to vegetable and other products, while they 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 poimlar 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 LiheUidd trimaciilata, previously figured, as 

 it furnishes some curious and interesting information, and may bo taken as representing that 

 of the group. 



When the female is about to deposit her eggs, she attaches her.self 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 larva; 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 inseots. 

 In this state it is longer than the larva and still more resembles the perfect insect. When 



about to become a perfect insect, the 

 pupa climbs up some suitable plant 

 near the surface of the water, and at- 

 taching itself firmly awaits the last 

 great change. In a short time the 

 skin opens down the back and the 

 adult Dragon fly, by bending back- 

 wards and forwards for some time, 

 emerges. It only requires to remain 

 a few hours, until its wings attain 

 their full size and hardness, when it 

 starts off on a life-long expedition of 

 plunder. 



In Fig. 43 we have a representa- 

 tion of three stages in the life of a 

 foreign LiheUuhi. The figure on the 

 left shows the larva using its mafk to 

 capture prey ; the figure on the right 

 represents the perfect insect in the act 

 of emerging from the pupa case. 



The full-grown Libc/lidu may be 



described as follows : — The body is 



^P- ''•'• much elongated and cylindrical, and 



attains a length of two inches, in average specimens. The iiead is large and bears two very 



large and prominent compound eyes. These eyes which consist of many thousand facettea 



each, are so large that they meet on the upper surface of the head. This great power of vision 



