SEA-FISHERIES LABORATORY. 349 



curator (Mr. T. N. Cregeen) during July, August, and 

 September, 1904 ; making a total of 327. All the fish 

 were placed in the spawning pond as soon as possible after 

 capture, and no difficulty was experienced in keeping them 

 in a healthy condition throughout the year. They were 

 fed daily upon mussels, with the addition of lug-worms 

 as often as the latter were procurable. The worms are 

 dug, for the most part, by the assistant, at Port St. Mary; 

 but the mussels have to be obtained from Lancashire, and 

 about one cwt. per week is required to keep the fish in 

 good condition. 



" The state of the pond has been quite satisfactory. 

 It was emptied and examined carefully in September, 

 1904, and again at the conclusion of the present spawning 

 season, in May, 1905, 



" The hatching apparatus was carefully overhauled 

 and put into working order during the latter part of 

 January, and was in continuous operation, without 

 mishap of any kind, from 14th February to 13th May. 

 The improvements in the structure of the tanks and boxes 

 alluded to in last report have now been effected, and have 

 resulted in a great saving of eggs during this season. 



" The first fertilized eggs of the plaice were found in 

 the pond on 14th February, IT days earlier than last year ; 

 and on the 17th there were 12,500 incubating in the boxes. 

 The daily yield of eggs gradually increased, until the 

 maximum was reached on 3rd April, when 313,600 were 

 collected. After this date the numbers ranged from about 

 224,000 to over 100,000 daily, until 25th April, when a 

 marked diminution was observed, and the last batch of 

 the season, numbering 45,000, was placed in the boxes 

 on 1st May. 



" The method of estimating the number of eggs was 

 essentially tiie same as that of last year. Ten dips with 



