SEA-FISHERIES LABORATORY. 207 



the first opportunity. In this he was successful, for on 

 boarding a trawler fishing on the off-shore grounds on 

 April 1st, mature Cod and Haddock were found, and the 

 eggs fertilized ; these were conveyed to the tanks in the 

 manner already described, so that when I returned on 

 April 9th, the embryos had been in the tanks for eight 

 days, and development had proceeded so far that the 

 larval fishes were clearly visible through the egg mem- 

 branes. Considerable mortality had taken place amongst 

 the embryos, and that continued to the end. 



" The embryos began to hatch out on the eleventh day 

 after fertilization, and the last of them hatched out the 

 following day. The larvae gradually dwindled in number 

 from day to day till at the end of seven days only one 

 remained alive ; the survivor was lost next day through 

 being carried away by the vessel accidentally overflowing. 

 Before my arrival the tanks had overflowed, the one into 

 the other, thus mixing the embryos so that it is difficult 

 to say now whether the larvae of both Cod and Haddock 

 were hatched. 



" This second experiment shows that it is possible to 

 hatch out the embryos in the tanks supplied with sea 

 water from the channel, and to keep the larvae alive for 

 several days after hatching. Further experiments are 

 necessary in order to ascertain for how long a period the 

 larvae can be kept alive by feeding them with ' plankton ' 

 collected in our tow-nets. 



"For the greater part of the time that the hatching 

 experiment was in operation, the water was used just as 

 it was taken from the channel, and during all that period 

 the weather was very unsettled, the sea washing up the 

 mud and making the water, on some days, quite turbid ; 

 the fine mud consequently got in amongst the embryos, 

 and, no doubt, had a bad effect upon them by adhering to 



