286 Fart III.— Twenty-second Annual Report 



course of the spawning season, the number stated in the paper may be 

 about right, viz., 5000. The duration of the spawning season is not 

 well known. The floating eggs were procured by the Garland from 

 23rd March to 19th August,* and it so happened that the extreme 

 dates were in the same year, so that the period mentioned, comprising 

 149 days or very nearly five months, may be taken to represent the 

 extent of the spawning season. How long the individual sprat goes on 

 spawning is not known, but considering that the period embraces the 

 warmest part of the year, and that growth is greater then, it is 

 probable that at least the 5000 eggs are shed. But even in that case, it 

 is evident that the sprat is one of the least fecund of fishes and, 

 so far as known, the least of all among the fishes whose 

 eggs are pelagic. Amid the varied complexities in the life of marine 

 fishes the explanation is not easy to discover. That the comparatively 

 early age at which the sprat may reach maturity is not the sole 

 explanation — though doubtless an important factor — is shown by the 

 fact that the whiting, which reaches maturity in its second year, 

 produces a ver-y much larger number of eggs. 



An Albino Plaice. 



Last year a few post-larval plaice were discovered in the hatching 

 apparatus, and among them was a small albino specimen, or one in 

 which the pigment was almost entirely absent. The only pigment 

 present was a few scattered chromatophores along the rays of the 

 dorsal, ventral, and caudal fins, on the anterior part of the head between 

 the eyes, the edge of the lower jaw, and between the jaw and the 

 pectorals, and about a couple of dozen of minute specks scattered over 

 the posterior half of the body, mostly near the tail. The eyes were 

 fully pigmented. The pigment was a dark umber. The body of the 

 little fish was transparent, the bottom of the hatching-box being visible 

 throvigh it. It lived for about a year, and it differed in habit from the 

 other small plaice living with it in that, while they were nearly always 

 on the bottom, it preferred the side of the box, to which it clung, close 

 to the surface of the water. The peritoneal lining of the abdominal 

 cavity shone through the tissues with a metallic bronze appearance. 



The Thickback {Solea variegata). 



Two specimens of this species of sole were taken in the small-meshed 

 net in the Moray Firth — the first on 27th December in 28 fathoms at 

 Smith Bank, and the other on the following day in 30 fathoms off 

 Burghead. They were both females — the first measuring 14-8cm. with 

 the roe well developed, and the second 16*3cm. The latter weighed 

 38 grammes, the ovaries weighing 1-1 grammes, and the eggs were well 

 advanced, the larger measuring •84mm. in diameter. It is evident, 

 therefore, that this fish spawns in the Moray Firth, but it is rare. 



It is common on the south coast of England, especially (according to 

 Cunningham)t south of the Eddystone, in from 30 to 40 fathoms. Two 

 specimens were taken by Holt during the Irish Survey. It has also 

 been occasionally captui'ed on the west coast of Scotland, Gunther 

 describing two immature specimens caught ofi' Can tyre in 65 fathoms 

 in March 1888,$ and a few small specimens have been taken by the 

 Garland in the Firth of Clyde. Day says that it was met with occasion- 

 ally off Banff by Edwards, but I have not traced the record, 



* Masterman — "A Review of the Work of the 'Garland' in connection with the 

 Pelagic Eggs of the Food Fishes," Ihid., Part III., Fifteenth Report, p. 234. 

 t " Marketable Marine Fishes " p. 259. 

 XProc. Roy. Soe.. Edin. xv., p. 220. 



