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Example of the growth of a species of fish, whose breeding- 

 season occurs in the month of January, and whose individuals 

 are c. 3 years in becoming „grown-up". 



January. 



December. 



m The constant curve 



All the lish thai ave more 

 than :; years old. 



Fish J voars 11 months 



old. 

 The line where the groups 



IT and III are amal^a 



mated. 



