PROPAGATION AND DISTEIBUTION OF FOOD FISHES, 1923. 85 



cent of the year's distributions were of this species, tlie remainder 

 being hirgemouth bass, rock bass, and snnfish, eacii of which ^Yas 

 produced in about the usual numbers. Adverse weather conditions 

 duiing tlie first half of April interfered with the spaw^ning season, 

 and shortly after nesting had begun a sudden cold spell occurred, 

 killing all eggs that had been deposited. Aside from this the season 

 was a normal one and, as four ponds had been devoted to the small- 

 mouth bass work instead of three as in past years, the final results 

 were larger by 57,000 than in 1922, the previous record year. This 

 extension of the work was made possible by the receipt of 150 adult 

 bass just prior to the spawning season from collections made in the 

 Lake Erie field. 



Adult bass for the enlargement and improvement of the brood 

 stock have been received annually from Lake Erie collections for 

 several years, some arriving in the fall and other lots in the early 

 spring. During the past three years these various lots of fish have 

 been segregated and special observations made with the view of 

 determining whether those acquired shortly before the breeding 

 season might be expected to produce as good results as the others. 

 While no definite conclusion has been reached, it is the opinion of 

 the station superintendent that this question is not a factor of par- 

 ticular importance, and that, other things being equal, spawning 

 may be expected to occur regardless of the exact time the fish are 

 received. 



During the months of July, August, and September an aquarial 

 exhibit of various species of fish collected from the Ohio River was 

 maintained and proved a great attraction to the large numbers of 

 visitors at the station. 



CAIRO (ILL.) SUBSTATION. 



The work at this point consists in salvaging food fishes that have 

 become stranded in the sloughs or pools formed by the periodical 

 flooding of the Ohio River. Owing to high water stages in these 

 sloughs the collections could not be undertaken during the early 

 fall. The work was started on November 13 and between that time 

 and December 2 fish to the num])er of 1,207,750 were removed from 

 temporary waters and returned to the river channel, the predomi- 

 nating species being catfish, crappie, and sunfish, in the order named. 

 The total cost of the operations amounted to $415, or an average of 

 less than 35 cents per thousand fish handled. 



MAMMOTH SPRING (ARK.) STATION. 

 [Dell Browx, Superintendent.] 



The work of repairing and improving the pond system, undertaken 

 during the jjast fiscal year at this station, was extended well into 

 the fall of 1922. Several unfinished pond banks were completed, 

 a new levee was constructed to replace one that had been destroyed 

 by muskrats, and 4-inch piping was purchased and installed to con- 

 nect several of the ponds with the water supply. A sufficient amount 

 of terra-cotta pipe for extending the supply to some of the unfinished 

 ponds was also provided but not installed. During September and 



