DRAGON FLIES. 73 



and then the water is shot out again. This move- 

 ment of the water aids in propelling- the insect 

 forward in the water. If a nymph be placed in a 

 dish with water to which a little fine sand has been 

 added, the movement of the water may be seen. 



The larvae and nymphs of the damsel-flies have 

 the gills externally placed, in the form of three 

 plate-like appendages to the tip of the abdomen, 

 and these gills are supplied with air tubes. 



By dragging a pond with a net. they can 

 easily be captured. These might be placed in a 

 glass jar, in which water plants are growing, and 

 then if supplied with mosquito wrigglers, their 

 development can be readily noted. A piece of 

 wood, or a rock risino- above the surface of the 

 water should also be placed in the jar, and finally 

 a piece of mosquito net tied over the top. We found 

 larvae in numbers on the roots of the water hya- 

 cinth. Taking just a single root of the plant, and 

 shaking it in a bowl of water, quite a number of 

 larvae were soon seen swimming around. They have 

 evidently found out that numerous small insects 

 live among these roots, hence the food supply is 

 plentiful. 



The larva undergoes from 12 to 15 moults in 

 growing up. Just before the final moult it becomes 

 listless and seems somewhat tired of its aquatic 

 existence. It crawls up out of the water, grasping 

 the stem of a water plant or any firm object that 

 is near. We have known these larvae to crawl 

 some yards from the pond before finally attaching 

 themselves. A short rest is indulged in, then the 



