Il6 REPORT OF THE COMMISSIONERS OF 



an easy matter to discover what any waters may contain in the way of fish food within 

 certain limits. Draw the net through the water amongst the weeds and water vegeta- 

 tion, and the solid matter will remain in the bottle while the water escapes, except such 

 as remains within the bottle. Fresh water shrimps will be readily seen, if they are 



Fig. 13. Test Net. 



captured, but it will require closer observation to discover Daphniaand Cyclops in the 

 bottle, and it should be tried in a strong light for this purpose. The net will serve a 

 two-fold purpose to test what may be in the water in the nature of fish food, and to 

 capture live food, Daphnia, Cyclops, and other insect larvae for transplanting into 

 waters that have been tested and found barren. 



It is reasonably safe to transplant any larvae that may be brought up in the net, 

 although there are insects more or less injurious to very young fish during some stage 

 of their existence, though not particularly so to the so-called game fishes. For 

 instance, the larvae of the dragon-fly, the " devil's-darning-needle," which is found 

 for the most part in standing water, is known to capture living animals, insects, 

 water snails (which by the way are excellent food for fish), tadpoles and even fishes. 



Tennyson must have watched the transformation of the larvae of the darning- 

 needle : 



" To-day I saw the dragon-fly 



Come from the wells where he did lie, 



An inner impulse rent the veil 



Of his old husk; from head to tail 



Came out clear plates of sapphire mail. 



He dried his wings ; like gauze they grew, 



Thro' crofts and pastures wet with dew 



A living flash of light he flew." 



