106 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 5 



CYCLE YEAR FOR MACKEREL BASED ON I8I7 

 6 8 lO 12 14 16 18 



20 



22 



Z 500 



J 450 



9 II 13 IS 17 19 21 23 2 4 6 8 



CYCLE YEAR FOR COD BASED ON 18I2 



FiGDEB 11. — Catch of mackerel and cod in the North) Atlantic, 23-year cycles from 

 1812 to 1931. Curve for cod shifted in phase 2 years. Dotted curved and dashed 

 curves are means of cycles I, III, V and II, IV respectively Full curves are general 

 means of all five cycles. 



