sea-fisheries laboratory. 97 



Herring Investigations. 



The scheme of biometric investigation of local herring 

 races has necessarily been abandoned in the meantime. 



Ten samples, of 24= herrings in each, were received during 

 the following months, part of May, June, July, August and 

 part of September. The August samples were cold- stored. 

 The samples came from the Manx summer herring fishery, 

 and were collected and forwarded by Mr. T. N. Cregeen, of 

 the Port Erin Biological Station. 



The herrings were examined for : — 



Length and weight as an index of i: condition " ; 

 Condition of the reproductive organs ; 

 Percentage of fat in the flesh. 



The samples were too small for biometric investigation. 



Length and Weight. 



The weight of the herrings, in proportion to their length, 

 rose during the season (with the exception of a singular set- 

 back in June). In September the weight began to fall off. 

 The increase in weight?, for herrings of the same length, was 

 due to the increase in mass of the reproductive organs, and 

 to the increase in depth and thickness of the fish, which " had 

 put on flesh." 



Course of the Fishery. 



The fishery began in May. The herrings were then in 

 Stage I. — virgins or immature, but sexually ripe fish. From 

 then on, the reproductive organs matured. In September all 

 were in Stage VII. , except one or two which were either virgins 

 or spent fish. None were found actually spawning (that is, 

 in the samples), and the fishery apparently came to an end 

 before spawning jwas universal. 



