of the Fishery Board for Scotland. 



221 



1 and a line along the dorsum of the intestine, besides various touches 

 1 of the same on the head and elsewhere. Stellate black chromatophores 

 ' occur along with the yellow, and in the early condition are present 

 1 on the yolk. The eyes soon assume a silvery aspect. The larval fish 

 1 is active and comparatively large, resembling in certain respects the 

 ' plaice. It is probably a pleuronectid.' 



When surveying the fishing grounds off the West Coast of Ireland 

 with Mr Green and Prof. Haddon in 1891, Mr Holt found that these 

 eggs pertained to the long-rough dab, and thus their comparative abund- 

 ance was readily explained. A similar relationship had been suspected at 

 St Andrews, since the ova of almost all the other pleuronectids except 

 the halibut had been examined. These ova are especially abundant on the 

 fishing grounds to the east of the Island of May. So far as my ex- 

 perience goes, they chiefly abound in March, rarely a few occur in 

 February, and in all probability, though nearly ripe, none are discharged 

 before January. Off the West Coast of Ireland Mr Holt found the 

 adults spawning during the same months, viz., from March to the begin- 

 ning of May. 



It is remarkable that the obscurity surrounding the eggs of so common 

 a fish should have remained so long. In a recent Scandinavian work * 

 nothing more definite than hearsay evidence is afforded, though the state- 

 ment of the fishermen of Bohuslan that the roe runs in February, and that 

 the fish is spent by the month of March, is near the truth. Moreover, 

 comparatively small specimens, both male and female, attain maturity. 



By the energy of Dr Fulton, a large consignment of living specimens 

 was forwarded to the Laboratory in excellent condition this spring, so 

 that an opportunity was given for a re-examination of the development of 

 this species. The ripe females ranged from 7 to 13 J inches, and all were 

 distinctly distended with the enlarged ovaries. Moreover, as they lay on 

 the dark bottom of the tank, the prominent ovarian region of the coloured 

 surface was readily distinguishable as a broad pale pinkish streak. Some of 

 the females were also marked with white touches, generally in pairs over 

 the interspinous regions dorsally and ventrally, — very much in the position 

 the dark touches hold in the pelagic post-larval forms. The males, on the 

 other hand, were much smaller, ranging from to 6| in total length, and 

 presenting little or no distention, — a fact due to the minute size of the 

 testes, which are wholly confined to the abdominal cavity, and arc only 

 about \ to f of an inch in length in a male of 6f inches. No larger male 

 occurred in this collection, which consisted of nearly sixty specimens, so 

 that the question may be raised as to the reasons for the limitation of the 

 size of this sex and the small size of the male organs. 



Most of the females were very ripe, and a considerable quantity of ova 

 escaped on the slightest pressure, and fell in a mass into the water, and 

 then slowly mixed with it. In the experiments made in the laboratory, 

 the smallest trace of milt fertilized every egg in the vessels, which were 

 about a foot across, so that the activity of the sperms was characteristic. 

 The quantity of ripe ova discharged at a given time was quite as large in 

 proportion as in the plaice, in the turbot, and in the flounder. Fishes in 

 which the testes are small, as in the torsk, plaice, long-rough dab, and sole, 

 do not appear to differ much — in regard to the rapidity of issue of the ripe 

 eggs — from those with large testes. The small size of the testes in the 

 horse, compared with the large size of the testes in the porpoise, is another 

 instance of the caution requisite in drawing conclusions on this head. At 

 any rate, in regard to fishes, the ascertained facts up to date do not 

 seem to warrant strong statements on the subject. The ripe female sole 

 in Scottish waters discharges a considerable number of eggs, and a large 

 * Scandinavian Fishes, Fries, Ekstrom and Sundevall. 2nd Edit., 1893. 



