18 Fishery Board for Scotland. 



Station 29. 



The presence of two plaice eggs in the " y " stage of development in 

 the collections in December 1904 has already been commented on. 



The only other observations at this station were made in the one 

 spawning year, namely, 1904-1905. 



Plaice eggs are the j&rst pelagic ones to appear in the plankton ; in 

 January they constituted over 95 per cent., and the percentage had 

 fallen to 30 in February. The relative frequencies of the eggs in the 

 surface hauls for January, February, and March are 46, 32, and 758 

 respectively, while the numbers of these in the first stages of develop- 

 ment are 28, 18, and 404. Just as at Station VII. the greatest fre- 

 quency occurs in March, even although the percentage of eggs in which 

 the embryo has passed through the first stages of development is almost 

 as high in January as in March. As the collections for both the 

 Dornoch Firth and Station 29 contain samples taken at corresponding 

 times during the spawning season 1904-1905, the frequencies of 

 the newly spawned eggs in the surface hauls may be compared 

 directly. 



Number of Newly-Spawned Eggs in Surface Net. 



Month. Dornoch Firth. Station 29. 



December 1904 3 



January 1905 264 28 



February 1905 42 18 



March 1905 4 404 



It is evident that spawning is later on these ofishore grounds than 

 in the Dornoch Firth. Further, it would appear that the area most 

 favoured by plaice during the spawning season varies slightly from 

 year to year. 



Station 30. 



As many observations were made at this station the records are 

 much enhanced in value. Notwithstanding the visits in December in 

 different years, no plaice eggs were taken in this month in the neighbour- 

 hood. Observations made in January 1905 and 1908 show how 

 variable the conditions may be from year to year. In 1905, on the 

 26th of this month, one egg was taken in the surface net, and in 1908, 

 as early as the 14th, 28 eggs were obtained, of which 26 were newly 

 spawned. The difference in frequency is much more marked if the 

 collections from the deeper water layers are compared. 



26th January 1905. 14th January 1908. , 

 Developmental Stages a, ^ y h Total. « |3 y 5 Total. 



