of the yearling bluegllls taken after false annull were first observed in the respective 

 species formed more or less distinct second annull; In 6 per cent of the bass and 10 per 

 cent of the bluegllls the second annulus was as definite as a true annulus, and might be 

 mistaken for It. 



8. In bass, scale measurements were found to be directly proportional to the length 

 of the fish. In bluegllls, this ratio was found to change as the fish grows. 



9. Stunted breeder bluegllls transplanted from Homewood Lake more than doubled thel 

 weight In 12 to 15 months In Fork Lake. These fish produced young In Fork Lake that were 

 heavier at 15 months than they had been at ages between 2 and 5 years when In Homewood 

 Lake. 



10. Water temperatures In Fork Lake remained about midway between minimum and maximi 

 dally air temperatures during the time covered by this study In 1939. The active growing 

 season for fish was about 6 months long. Transparency and water levels were closely cor- 

 related with rainfall. Fork Lake Is thermally stratified from late spring to early fall. 

 Artificial circulation was produced with a small outboard motor. 



11. Bluegllls spawned at the age of 1 year, but the bass did not. The spawning 

 period for bluegllls extended from early June through August. 



12. Analjrses of bass and blueglll stomachs In 1939 showed some competition for In- 

 sects. All fish and crayfish In these stomachs had been taken by bass, and almost alf" ol 

 the entomostraca, vegetation and mollusks by bluegllls. 



13. The hook-and-llne catch In Fork Lake averaged 4.37 fish per man-hour. The catcl- 

 viere greatest when the water was clearest. v 



LITERATURE CITED 



Cooper, Gerald P. 



1936. Food habits, rate of growth and cannibalism of young largemouth bass (Aplites 

 salmoides) In state-operated rearing ponds in Michigan during 1935. Trans. 

 Am. Fish. Soc. 66:242-66. 



Greaser, Charles W. 



1926. The structure and growth of the scales of fishes in relation to the interpre- 

 tation of their life-history, with special reference to the sunfish, Eupomoii 

 gibbosus. Univ. Mich. Misc. Pub. Mus. Zool, 17:1-82. 



Ellis, M. M. 



1937. Some fishery problems in impounded waters. Trans. Am. Fish. Soc. 66:63-75. 

 Hansen, Donald F. 



1937. The date of annual ring formation in the scales of the white crappie. Trans. 

 Am. Fish. Soc. 66:227-36. 



Hubbs, Carl L., and Gerald P. Cooper 



1935. Age and growth of the long-eared and the green sunflshes in Michigan. Papers 

 Mich. Acad. Scl., Arts and Letts. 20:669-96. 



James, Marian F. 



1939, Studies on starvation in largemouth bass. Trans, 111, Acad, Scl. 32(2) : 220-1 



Msirkus, Henry C. 



1932. The extent to which temperatiire changes influence food consumption in large- 

 mouth bass (Euro floridana). Trans. Am. Fish. Soc. 62:202-10. 



Thompson, David H., and George W. Bennett 



1938. Lake management reports. 1. Horseshoe Lake near Cairo, Illinois. 111. Nat. 

 Hist. Surv. Biol. Notes 8. 6 pp. 



1939a. Lake management reports. 2. Fork Lake near Mount Zion, Illinois. 111. Nat. 

 Hist. Siirv. Biol. Notes 9, 14 pp. 



1939b. Lake management reports. 3. Lincoln Lakes near Lincoln, Illinois. 111. Nat. 

 Hist. Surv. Biol. Notes 11. 24 pp. 



24 



