370 NOTES ON EXPEEIMblJSTS RKLATING TO THE 



a matter of experience, i. e. of continued experiment. It has already 

 once (1885) been done by Captain Dannevig in Norway ; and if any 

 benefit come to the lobster fishery by turning the newly hatched 

 larvfe loose in their most helpless phase, greater success will cer- 

 tainly attend the planting of over-fished grounds with young lobsters 

 at the age at which they sink to the bottom and assume the habits 

 of concealment of the adult. 



J.I. The Rearing of Lakval Fish, 



By J. T. Cunningham, M.A., F.R.S.E. 



The Flounder {PUuronectes flesus, Linn.). — On May 3rd of the cur- 

 rent year I received from Mr. Dunn, of Mevagissey, about 200 young 

 flounders [Pleuronectes jiesus), collected in the shallow pools left in 

 Mevagissey Harbour at low tide ; and on May 7th Mr. Dunn sent 

 another large consignment of the same kind of fish. I put the 

 greater number of them into two shallow table-tanks, one of these 

 tanks being in the aquarium and exposed to a good deal of light, 

 the other in the Laboratory and somewhat dark. 



These young flounders were at the stages of development repre- 

 sented in fig. 5, PI. XVII, and fig. 1, PI. XVIII of my Treatise 

 on the Sole, the great majority at the younger of these two stages. 

 They were very transparent with the exception of the eyes, which 

 were fully pigmented and had a brilliantly metallic appearance. 

 The metamorphosis in these was begun, but by no means completed ; 

 the left eye was approaching the edge of the head, and nearly all 

 the pigment-cells had disappeared from the left side of the body. 

 They rested for the mo^t part on the bottom, but frequently swam 

 about in the water in a slanting position. One of these was measured, 

 and found to be 12'7 mm. {\ inch) in length, 5'1 mm. [-^ inch) in 

 breadth. 



Some of them were slightly more advanced ; these were much 

 more opaque, with more pigment on the upper side, and with the 

 eye of the lower side on the very edge of the head. One of them 

 measured 11 5 mm, in length and 5 mm. in breadth. 



The tanks in which these young flounders were placed were 

 arranged thus : the bottom was covered with fine sand, except where 

 at one end there was gravel, separated from the sand by a wooden 

 plank, and filling up a space below the slate partition which 

 separated this tank from the next. Water, flowing into the tank 

 in a couple of small jets, passed through the layer of gravel, so 

 that the level in the tank containing the flounders was always the 



