MARINE BIOLOGICAL STATION AT PORT ERIN. 



37 



October 3rd — 162 days after they were hatched. Twelve 

 taken at random varied in length from 1J inch to 2J 

 inches, the average length being If inch. The same 

 number taken from the eastern portion of the pond, the 

 exact age of which is not known, showed much greater 

 uniformity in size, and their average length was 3J inches. 

 These young fish had apparently thriven better in 

 association with about 250 adults than those in the other 

 portion of the pond, where there were no organisms of 

 larger size to compete with them for the great swarms of 

 Copepoda and other organisms upon which they were seen 

 to feed. 



just hatched 



Fig. VII. — Larval Plaice, x 15. 



The first fertilized eggs were seen in the pond ou 

 February 13th, and a small number were placed in one 

 of the hatching boxes two days later. Thenceforward 

 the numbers increased almost daily until April 2nd, 

 when the maximum number of 511,000 was obtained. 

 The last fertilized eggs were collected on May 1st, 

 bringing the total to 6,072,600, and the total number of 

 larvse hatched during the season was 5,431,500. This 

 was an increase of 335,000 compared with the total of the 

 season of 1905 ; but, inasmuch as the number of spawners 

 was smaller than that of the previous year (275 against 

 319 in 1905), the figures given do not indicate the full 



