Flounder Migration, Food, Growth. 41 



within brackish water area, and the tidal flow carries the 

 eggs into the creeks, where hatching proceeds apace. Thus 

 it is that the sandy and muddy Ray, and other such like creeks, 

 virtually become rearing places of the flounder, even supposing 

 that the actual spawning ground is outside. We cannot say, 

 then, that in our estuary, or hereabouts, we have detected a 

 regular wholesale migration from the river far seawards, as has 

 been assumed to take place in other districts ; but alone a 

 periodical shifting from the fresh to brackish water as 

 mentioned. 



The regular breeding season in the Thames is the first 

 three or four months of the year, but evidently on quite excep- 

 tional occasions it is prolonged. For example, R. Johnson, a 

 reliable observer, states that in the middle of August, 1899, 

 he captured in his trawl a full (" hard ") roed female near 

 the Oaze. 



The notion that in some cases young flounders are hatched 

 out on the parent's back has still a few believers. One unusually 

 well-informed fisherman insisted he would prove the fact, and 

 indeed produced examples of the said peculiarity. Even when 

 he was shewn under the microscope that the egg-like tumours 

 contained parasitic worms and not embryo fish, he left only 

 half convinced that he was wrong. 



The food of these estuarine flounders are ragworms, lob- 

 worms, and minute annelids, also small shrimps, Mysidae, 

 Corophium, Idotea; in sparse cases young mussels, Tellina, 

 weeds and other vegetable debris. 



Of those flounders in the Ray, the average rate of first 

 year's growth appears to be something near Mclntosh's estimate 

 of 4 to 5 inches ; but the presence of smaller ones complicates 

 the question ; though Cunningham's suggestion that they do 

 not breed at this age seems quite feasible. 



What flounders are captured by the Leigh fishermen find 

 local customers, for they are very rarely indeed sent to the 

 London market. Though not much run on by the people, 



