190 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



March 14th. The plaice commenced to spawn three 

 days later. During the last dozen years the date on 

 which fertilised eggs were first obtained from flounders 

 in the tanks has varied from February 28th to 

 March 14th. Only once before, in 1906, has the 

 spawning of the flounders been so late, and that was also 

 on March 14th of that year. The spawning of the plaice 

 kept in the tanks has varied from March 4th to 

 March 21st. The spawning of the fish in 1912 lasted for 

 nearly seven weeks. During that time, one million 

 two hundred thousand plaice eggs were obtained, and 

 thirteen million seven hundred thousand flounder eggs. 

 The eggs were incubated in the usual way in the 

 Dannevig hatching apparatus, and the resulting fry 

 were afterwards liberated in the sea. The incubation of 

 the plaice eggs varied from sixteen days during March to 

 fourteen days in April. The flounders required eleven 

 days to incubate in March and seven days in April. At 

 the end of the spawning time, when the adult plaice 

 were finished with, a few of them were marked by 

 Mr. Johnstone and liberated outside Walney by 

 Captain J. Wright, when he was taking the fishermen 

 across to Fleetwood after the completion of one of the 

 classes. The remainder of the adult fish were set free 

 in the channel off Piel. 



The following tables give the number of eggs 

 collected, and of the fry hatched and set free on the 

 dates specified : — 



