264 Part III. — Twenty-secoyid Annual Report 



The question of attempting to rear the fry on a fairly large scale has 

 been considered. It not unfrequently happens that at the end of the 

 hatching season young metamorphosed plaice are found in some part of 

 the apparatus, which have succeeded in passing the post-larval stages, 

 although it is not easy to get such forms when it is attempted to rear 

 them. The difficulty is in providing a supply of suitable food, and it is 

 proposed to utilise a tank to act as a receptacle for spawning invei'te- 

 brates, so that the water, enriched with the embryos and larvae may be 

 used to supply the young fishes. 



For a few years the placing of the fry in Loch Fyne has been inter- 

 mitted, and they have been distributed, as descidbed, along the coast of 

 Aberdeenshire. The reason for doing so is in order to enable observa- 

 tions as to the abundance of young plaice on the beaches in Loch Fyne 

 to be made under natural conditions, without artificially reared fry being 

 placed there in the same season, and the push-net examination of these 

 beaches is being continued each summer. The fry were originally 

 taken to Loch Fyne without such observations having been made 

 beforehand, and there were therefore no data for comparing the abun- 

 dance of the young plaice in the years in which the fry were put into 

 the Loch. From the natural fluctuations which take place with fish 

 everywhere, it is obvious that it is desirable to have observations carried 

 on long enough to be able to distinguish one cause of fluctuation from 

 the other, just as in cases where the influence of a method of fishing, or 

 of stopping it, requires to be tested in the same way. 



During the hatching season the hatchery was visited by depvitations 

 of fishermen from the coast of Aberdeen, as in previous years, at the 

 request of the Technical Education Committee of the County Council, 

 and they received demonstrations as to the processes employed. 



[Tables. 



