ELEVENTH ANNUAL REPORT. 



97 



are useful in small ornamental ponds in destroying the larvcC of 

 mosquitoes. 



The full use of the fish crop of a large natural pond or lake 

 can seldom be secured by ordinary fishing. It is necessary that 

 seines and trap-nets be used. Experience has proved that such 

 ponds usually contain many large fishes which will not take the 

 hook. 



A deep spring-fed lake on Long Island had for years furnished 

 only moderately good bass fishing and no one imagined its wealth 

 of fishes until the embankment which formed it gave way and 

 distributed hundreds of good sized black bass on the flats below, 

 many of them weighing from four to six pounds. It is possible 

 that these fishes were so well fed on the small frv of their own 



CROSS-SECTION OF THE DAM. 



A — Embankment. B — Ground-Ditch. C — Solid Ground. D — Water. 

 F — Penstock. H — Sliding W'ater-Boards. 



E — Drain. 



kind, as well as other species coming over the dam from the pond 

 above, that what the angler could ofifer did not tempt them. 



The introduction of new adult stock may be desirable in an old 

 pond where there has been in-breeding, but overstocking is the 

 main trouble, the remedies for which are thiiming-out and re-es- 

 tablishing the food supply. 



Owing to the customary preference for "game fishes," many 

 excellent pond species, such as rock bass, calico bass, yellow- 

 perch, white perch, long-eared and blue-gilled sunfish and catfish, 

 have been overlooked. Other kinds such as the warmouth or the 

 white bass, inhabiting waters of the south or middle west, are 

 equally desirable. All of these fishes increase rapidly, take the 

 hook readily and are good food-fishes. They will multiply in 



