86 American Fisheries Society 



have been measured and the stomach contents examined. 

 The growth made by the fishes in the three ponds, up to 

 September 2, is given in the following table. 



Referring to table No. 1, it will be noted that the fish 

 reached the largest size in Pond 1 E where a maximum 

 length of 4.37 inches and an average length of 4.05 inches 

 had been obtained by September 2, being an increase of 

 3.81 inches an 3.53 inches over the original measure- 

 ments started with. This is quite a remarkable growth 

 to be made in approximately two months time. Though 

 smaller at the commencement, the fish in Pond 4 E had 

 reached a greater size by August 19, than the ones in 

 Pond 9 D, and continued in the lead. As the fish in Pond 

 1 E had also grown faster than the ones in 9 D, the natu- 

 ral supposition would be that there was less available 

 food in the latter pond, per number of fish, than in the 

 two other ponds. 



Food 



The stomach contents of the fishes taken in the weekly 

 collections were examined by Mr. N. K. Bigelow, tempo- 

 rary scientific assistant, and the following data on the 

 food have been compiled from the detailed notes supplied 

 by him. Table No. 2 gives the total number of fish ex- 

 amined, the size ranges for each pond and the percentages 

 in which the various food items occur. 



Referring to the foregoing table, it will be noted that 

 by far the greater part of the food of the fish in Pond 1 E 

 was composed of insect larvae, fully 74 per cent consisting 

 of these forms. Chironomus larvae was the most impor- 

 tant item of food, 55.9 per cent of the total food taken 

 consisting of these forms. Ephemerida larvae were 

 taken in less numbers, making up 9.4 per cent of the food. 

 Collections of the various forms in the pond made by 

 George B. Lay, temporary scientific aid, revealed the 

 presence in considerable numbers of both Chironomus 

 and Ephmerida larvae. Thus it would seem that the ex- 

 ceedingly larger number of Chironomus larvae was 

 taken more from choice than the fact that the Ephmerida 



