How to obtain it. 215 



which may be found on some of the marginal plants, grasses, etc. 

 The larval stage of these insects is passed in the water, where they 

 are free swimming crawling creatures, predatory in their habits, 

 and do not possess a protective shell of any kind. Most of them 

 thrive best in running water, and if once introduced, and the 

 water suits them, they multiply rapidly. The various methods of 

 introducing flies to unstocked waters are well worthy of con- 

 sideration. The work, like most others, has its difficulties, but I 

 apprehend that there is no reason why these apparent difficulties 

 should not be bridged over. Many of the larvae are very sensitive 

 to changes of water, and this is one of the difficulties that we have 

 to contend with. It can be overcome by using care in trans- 

 planting. The creeper, or larvae of the stone fly, is very tenacious 

 of life, but even it requires care in its treatment, or it will not 

 always be found to succeed on being introduced to "pastures 

 new." 



The alder fly (Sialis luteria], the black fly which folds its 

 wings along its back, and spends much time sitting on a fence in 

 the sun, or bobbing about on the water in swarms, is best moved 

 in its egg stage. It lays a hundred eggs or more, which are 

 deposited in neat-looking rows on herbage near the water. Careful 

 observation would soon discover these, and it would be much 

 safer and easier to collect and transmit them than to catch and 

 carry the larvae, and there would be a much better chance of a 

 good result. The introduction of the perfect insect is a mistake, 

 and is probably useless, unless ample protection is given to them 

 and also to their eggs. In the case of some species it may be 

 done by building an insect house, and having had considerable 

 experience as an entomologist, and bred and reared thousands of 

 insects in this way, I can speak with tolerable certainty as to the 

 result. But there are few persons probably who could, or would, 

 devote the time required to look after such an undertaking, and 

 without proper attention it would be a failure. 



Previously to the deposition of the eggs, it may be noticed 

 that both caddis and stone flies carry them in a bunch at their 

 posterior extremities; and what angler does not know the grannom 

 fly, or green tail (?), a brown-looking fellow, who often carries a 

 bunch of greenish-looking eggs behind him. They are exceed 



