LIFE HISTORY OF LAKE HERRING OF LAKE HURON 



383 



In a ripe fish the sex products are easily pressed out of the body. In a spent or 

 spawned fish the gonads are soft and flaccid. 



Table 50 shows the proportion of inimatiu-e male and female fish found in each 

 age group of each collection. The data of this table are arranged like those of Table 

 47. As the herring samples were taken on the breeding grounds, it is to be expected 

 that a large percentage of each would consist of sexually matured fish. Only 3 per 

 cent of all the herring taken, 1.3 per cent of all the males and 3.3 per cent of all the 

 females, were sexually immatm-e or nonspawning fish. The percentage of nonspawn- 

 ing males varied from to 4.3 per cent in the four collections and females from 1.7 to 

 7.8 per cent. The higher percentages of both sexes occurred in the year 1922. 



Table 50. — Relative abundance of immature and sexually mature males and females in samples of lake 

 herring taken 1921, 1923, 1923, and 1924 at Bay City, Mich. 



' The following immature fish are not included; 1 female ( 

 2 females (?), and 11 flsh, se-t undertermined, of age group III; 

 ' The Ssb mentioned in footnote 1 included. 



') and 3 individuals, sei undetermined, of age group II; 2 males (?) , 

 1 fish, sex undetermined, of age group IV. 



