SEA-FISHERIES LABORATORY. 119 



In the June sample three fish were noticed in a more 

 advanced state of maturity than the majority of the sample — 

 two in Stage IV and one in Stages IV-V. There is evidence, 

 from size and scale markings, that these fish belong to a group 

 similar to the fish hi the September sample at Stage V. This 

 being the case, it would suggest that it has taken approximately 

 ten weeks for the herrings to advance from, say, Stage IV 

 to Stage V. And again in the September sample, two fish 

 show a less advanced stage of maturity than the majority, 

 being hi Stage III. Evidence from length and scale markings 

 suggests a possibility of their belonging to a group similar to 

 those in Stage II in June, so that if the assumption were 

 permissable, it would hidicate that they had advanced from 

 Stage II to Stage III in approximately ten weeks. 



Although the data are small, they at least indicate one 

 of many points which it is hoped will be found possible to 

 investigate during the present year. Another interesting 

 point arises, inasmuch as the fish curers stated that two weeks 

 previous to the September sample, nearly all the fish passhig 

 through their hands were Spents (= Stage VII) and taken 

 from the same grounds. Unfortunately we have no data, and 

 nothmg can be said in confirmation of this. 



They stated, however, that they were similar in size to 

 the September sample, and were uncertain how long this supply 

 of spent fish lasted. 



That there are spawning grounds hi the vicinity of Isle 

 of Man seems certain when a spent population is replaced by 

 another about to spawn, 3-72 % actually spawning, and 

 4-54 % finished spawning. Furthermore, conditions are 

 favourable on these grounds where there is abundant Laminaria, 

 rough ground and deep water of about 20 fathoms. 



