ARTIFICIAL HATCHING OF MARINE FOOD-FISHES. 257 



flat-fish in the British seas, and, moreover, it is tolerably 

 hardy, so that it can be reared from young stages to the 

 adult condition in tanks and confined areas of sea-water. 

 The latter is also a valuable food-fish, and is hardy at all 

 stages, while its comparative rarity in the neighbouring 

 waters will make any increase after such operations unmis- 

 takable. A considerable number of soles had been col- 

 lected last autumn and kept in the enclosed tidal creek at 

 Dunbar, but as their spawning-season is somewhat late, it 

 was decided to occupy the early spring months by experi- 

 menting with the plaice. 



Steps were taken to secure adult plaice from the off- 

 shore grounds early in the season by aid of the Garland, 

 and others were obtained on board various trawlers, though 

 many of these afterwards succumbed from injuries received 

 in the trawl. When the period for transference to the 

 spawning-pond arrived, it was found that of fifty-eight 

 adult plaice which had been confined for some months in 

 the tidal-creek and had thus become acclimatised to their 

 new life, all survived, while there was considerable mortality 

 amongst those recently received. The greatest number of 

 plaice in the spawning-pond at a given time was three 

 hundred and ninety, and the whole number experimented 

 with three hundred and ninety-six — a comparatively small 

 total when contrasted with the large number of cod kept in 

 confinement during the operations of the Americans. The 

 average size of the males was 17! inches, and of the 

 females, 204 inches. The fishes fed readily in the spawn- 

 ing-pond, and swam actively about. 



Spawning commenced in earnest on the 9th March, on 

 which day two hundred and twenty-five thousand ova were 

 collected, and continued till the 8th May, the total number 

 of ova obtained during this period being twenty-seven 

 million three hundred and fifty thousand. These large 

 eggs had been hatched at the St. Andrews laboratory 

 every season since 1884, and the larval fishes were known 

 to be hardy, so that a good return was expected. Accord- 

 ingly it was found that the number of larval fishes placed 

 in the sea was twenty-six million and sixty thousand, the 



