SEA-FISHERIES LABORATORY. 108 



to the stock of young flat-fish, in the Irish Sea. Last 

 spring over five million plaice fry were hatched from six 

 million eggs and were successfully set free in the open 

 sea to the south and west of the Isle of Man. 



As before, a certain number of the larvae have been 

 left throughout the summer in the open-air spawning 

 pond at Port Erin and reared through their metamorphosis 

 into young plaice. It is very interesting to note that 

 of these young fishes, all of the same age, while 

 those left in the larger pond, under more natural 

 conditions, had attained by September (say five months' 

 growth) a size of up to nearly five inches in length (the 

 average of 12 being 3^ inches), a few that had been placed 

 on exhibition in the Aquarium in a white enamelled 

 basin, although regularly fed, in the same time grew to 

 only one inch. A few thousand put in the smaller 

 western part of the pond were sampled on October 3rd, 

 162 days after hatching. Twelve taken at random varied 

 in length from 1| inch to 2J inches, the average length 

 being If inch. 



The classes for fishermen at Piel laboratory have been 

 held as usual, and with the usual success. The details 

 are given in Mr. Scott's Report below. 



Sea-Fish Hatching in Norway. 



I print two interesting statements sent to me by 

 Captain Dannevig and Mr. K. Dahl, dealing with the 

 supposed results of adding artificially hatched cod larvae 

 to certain Norwegian fjords. These investigators not only 

 write from very different points of view, but unfortunately 

 they do not deal with exactly the same series of observa- 

 tions, so that it becomes difficult to compare their results, 

 and, in fact, on a superficial examination it might be 

 supposed that no correspondence could be traced between 



