LIFE HISTORY OF LAKE HERRING OF LAKE HURON 



387 



Table 53. — Range 



in length, modal length, average length of samples, and average actual length oj 

 each age group for the combined samples of herring taken at Tobico, Nayanquing, Au Gres, and 

 Gravelly Point in Saginaw Bay ' 



1 The number of specimens employed is shown in parentheses. 



Table 54. — Comparison of computed lengths of each year of life of corresponding age groups of herring 

 collected at various localities in Saginaw Bay 



' The last value of each horizontal row represents actual measurements of flsh. 



Examination of Tables 53 and 54 shows that beyond any question the Tobico 

 and Nayanquing herring belong to the same general population. The range in 

 length, the average size of the sample, and the average actual and computed lengths 

 of the age groups are virtually identical in the two collections. The modal and the 

 average length of the Au Gres and the Gravelly Point herring are somewhat less than 

 those of the Tobico and the Nayanquing fish. Examination of the actual lengths 

 of Table 53, however, shows that this decrease in size is due entirely to the small aver- 

 age size of the 3-year fish. Those of Gravelly Point are noticeably small. As stated 

 on page 385 the small size of these fish is due to the 3-year individuals taken Novem- 

 ber 30 (Table 51). The 3-year herring taken at Gravelly Point on December 4 

 reached about the same average length as those taken at Tobico, Nayanquing, and 

 Au Gres (Tables 51 and 53). Mr. Brackenbury, a fisherman who has fisheci at Grav- 

 elly Point for the last 32 years, states that large numbers of small herring come on 

 late in the fall after the main run of herring is over. This late run, he states, is com- 

 posed principally of males. Our November 30 sample may include part of such a 

 late run, although the 3-year fish of this sample are mostly females (75.6 per cent). 

 The differences in length between the 3-year herring from Gravelly Point and those 



