EXPEEIMENT STATION REPORT. 655 



The selection of the places for making the experiment was gov- 

 erned in tlie main by the desirability of convenience in maintain- 

 ing some sort of espionage over them dnring the winter. 



One of the small streams leading to the Westville pond comes 

 from springs at jSTorth Woodbnry. Another comes from the direc- 

 tion of the Delaware river, and it is now believed that in time of 

 heavy rains small fishes could make their way to similar small 

 rlvnlets lloAving to the Delaware, but dense growths of briars pre- 

 vent a complete examination. It mnst be, therefore, a matter of 

 conjecture whether these fishes were devoured by the black bass, 

 pike, yellow perch and sunfish inhaljiting the Westville pond, or 

 whether because of their enemies or dislike to their clianged condi- 

 tions they found their way during the spring rains to rivulets flow- 

 ing to the Delaware. Some of them were seen during the winter 

 and as late as l[areh half a mile or more above the pond, and some 

 still further up. 



The Westville pond was looked upon as the most favorable in 

 this section for the experiment, as affording average conditions, 

 the possibility of escape by pushing up the rivulets leading to it 

 not then being suspected ; this, however, as before stated, being at 

 present a matter of conjecture only. 



When the fish were deposited the temperature of the water in 

 the rivulets at Westville was about 45° F., or spring water tem- 

 ]x>rature, and they seemed oomfortahle in it, but soon took refuge 

 from the current in the grasses fringing the banks, disappearing 

 completely from sight. In the other places the water was colder 

 and the conditions more unfavoraMe and none of the fish were 

 seen afterwards, and they probably succumbed to the cold or were 

 devoured. In the ponds of the Aquarium Supply Company hun- 

 dreds of young pike about one-half to three-quarters inch Mng were 

 found in March, the breeders having found their way in through 

 muskrat holes in the banks. In about sixty days they were four 

 to five inches long, but not so numerous, their development repre- 

 senting the destruction of their kindred and all other species. It 

 is the presence of the predaceous species everywhere that makes 

 such experiments so difficult. In recommending that the supplying 

 of fishes for the purpose of mosquito extermination l>e placed in 

 the hands of the State Fish Commission,, if it be deemed desirable 

 to continue the experiment, the writer is actuated by the belief 



