128 American Fisheries Society 



the same car. The extruded eggs were observed for the 

 first time on April 15. The first of the fry appeared 

 April 22. 



The conditions under which the fry were hatched and 

 reared approached very nearly natural conditions. The 

 apparatus and the principles involved have been fully de- 

 scribed by Dr. A. D. Mead in his papers on lobster rear- 

 ing. The larger lots were hatched and reared in the rear- 

 ing boxes in which the screens over the windows were 

 replaced by sand filters. This was made necessary by the 

 minuteness of the fry. 



In rearing small groups for close observation a slightly 

 different type of apparatus was used. The young were 

 hatched and kept in cheese-cloth cylinders. The cylinders 

 were about two feet deep and one foot in diameter. These 

 were either fastened to the sides of the rearing boxes or 

 allowed to float free. The rearing box in either case sim- 

 ply served as a breakwater. These cylinders were first 

 designed by Mr. Barnes of the Wickford Hatchery. No 

 difficulty was experienced in keeping small numbers in 

 shallow dishes in the laboratory. The dishes were in all 

 cases covered to keep out the dust and the water was 

 changed every second day. 



At Woods Hole the fry were taken directly from the 

 rearing jars and kept in shallow dishes in the laboratory 

 or in cheese-cloth cylinders in the harbor. In the latter 

 case storage cars were used as breakwaters. 



In describing the young of the winter flounder, four 

 stages may be chosen that will show all the diagnostic 

 characteristics for the purposes of identification from the 

 time of hatching to the end of the second month. Stage 

 1 is the young fish at hatching and the description for 

 this stage would apply equally well to the earlier stages 

 in general. Stage 2 shows a fish of twelve days. It dif- 

 fers from Stage 1 in that the yolk is completely absorbed, 

 the fin rays are beginning to appear and the pigment has 

 a much wider distribution. Stage 3 is a fish of about 

 40 days and can be taken as representative of all fishes 

 in which the eyes have reached the position shown in 



