Aquatic Insects in 



the larva maintains a current of water 

 through its case. There are a great 

 many species of caddis-flies, occurring 

 in all parts of the world in various 

 situations, some few even living in 

 very brackish water. A marine species in 

 New Zealand forms its case of coralline 

 seaweeds. 



Some of the universally admired 

 dragon-flies are among the largest of 

 known insects, and fossil remains indi- 

 cate the former existence of a species 

 measuring eighteen inches in length. 

 They are found all over the world, and 

 their larvae inhabit ponds and streams, 

 leading a purely aquatic existence. 

 Dragon-fly eggs are in some instances 

 dropped freely into the water, and in 

 others are attached to the stems of 

 aquatic plants. Some species insert the 

 eggs in the plant tissues. There are two 

 kinds of larvae, one kind being the off- 

 spring of the big type of dragon-fly so 



