of the Fishery Board for Scotland. 287 

 The quantity and numbers for each month were : — 





No. 2. 



No. 5. 



C.C. 



No. 



C.C 



No. 



March, . 

 April, . 

 May, . 



71-82 

 582-47 



15,605 

 147,952 



263-2 

 559-29 

 34-30 



65,414 

 176,456 

 10,907 



The quantities taken for enumeration were 84*94 cubic centimetres for 

 No. 2 and 77 - 04 for No. 5, or about 13 and 9 per cent, of the totals ; and 

 the numbers of eggs counted were 19,075 of No. 2 and 21,400 of No. 5, 

 the total being 161-98 cubic centimetres, and 40,475 eggs. 



With regard to the fecundity of the fishes, these results agree very well 

 with those deduced previously from weighing part of the ovary and 

 enumerating the eggs. Thus, in the paper referred to in the Ninth Annual 

 Report, I describe a female of 17| inches, and weighing 2 lbs. 10 ounces, 

 with an estimated number of 148,470 eggs, and another of the same size 

 and weighing 3 lbs. 0| ounces, with 223,497 ; the average for the five 

 plaice there dealt with being 19*9 inches in length, 3 lbs. lOf ounces 

 (1664 grammes) in weight, and 301,394 eggs. 



Before referring further to the facts brought out in the Table, I may 

 describe some of the occurrences in regard to the fishes and their 

 treatment. 



On 31st March a fresh male quite ripe was put into tank No. 5. The 

 female was observed to be lying apart from the males, all of which had 

 conspicuous red spots, but not nearly so bright as one often sees on 

 plaice brought to deck at the fishing grounds at other times of the year. 

 The ovaries were sometimes enormously swollen, so much so that I was 

 afraid that the " egg-bound " condition was about to supervene. It 

 appears, however, to be natural, and a certain distension occurred before 

 the eggs were allowed to run from the oviduct. After a " burst" of 

 spawning they were notably reduced in size. 



On the 6th April, a fresh ripe male was put with No. 5, and the 

 spawning, which had been interrupted, began on the same night. On 

 the occasions when No. 5 stopped spawning, she was usually observed to 

 be lying away from the males. The latter, it may be remarked, appeared 

 to have no contests for the privilege of fertilising the eggs, as with the 

 lumpsuckers in an adjoining tank. They were always lying quietly, and 

 often, or even usually, together. 



The ovaries of No. 2 were, as a rule, more swollen than those of the 

 other female. 



On 13th April two ripe males were put into No. 5, and she spawned 

 again on the 15th. 



With regard to food, mussels were only occasionally eaten, probably 

 by the males ; only on one occasion was any slimy matter which might 

 have come from the intestines observed in the overflow, and in pressing 

 the plaice taken from the tank to select those for the experiment, no 

 excrements were pressed out. 



After No. 5 stopped spawning on the 26th, she was observed to be 

 adhering to the vertical side of the tank, a position she occupied for a 

 day or two, as if desiring to be freed from the attention of the males. 



Spawning was never actually observed, but the Table shows that it 

 takes place usually at night, though it does not always do so (see 27th 



