of the Fishery Board for Scotland. 



00 



Pollack. The eggs of pollac"k were found in Loch Fyne in March, 

 April, May, and June. February (?) to May is given as the spawning 

 period by M'lntosh and Masterman. 



Witch. The eggs of this form appear in Loch Fyne in April, and are 

 to be found every month until August. May to September and May to 

 July are the spawning periods given by Fulton, and M'lntosh and 

 Masterman, respectively. 



Ling. The eggs of this fish were captured in April, May, June, and 

 July, but not in sufficient numbers to warrant any inference as to the 

 spawning period. 



Solenette. Three eggs only were obtained — one each in March, April, 

 and May. 



Rockling. The eggs of the different rocklings have not been separated, 

 but the majority belong to the five-bearded species. Rockling eggs 

 appeared in January along with the eggs of the dragonet, and were to be 

 found in Loch Fyne right on till August. The largest number of eggs 

 are found in April. 



The curve of spawning of a fish does not rise gradually to its greatest 

 height and then sink at a rate equal to that by which it rose. The rising 

 portion of the curve is usually much steeper than the sinking portion. In 

 other words, there is more regularity in the time of the opening of a 

 spawning period than there is in ending it. Very shortly after spawning 

 has commenced the majority of the species will be spawning, and the 

 height of the spawning period is soon reached ; but after the majority has 

 ceased spawning a few individuals may carry on spawning for a month or 

 more longer, and the curve acquires a very gentle downward slope. This 

 may be seen by reference to Table XII p. 96. It will 

 be noticed that in many cases the height of the spawning of any one 

 species takes place about a month or two months after spawning com- 

 mences. The egg, however, is found for several months after the height 

 of the spawning period is passed. In certain cases, which appear to be 

 exceptions, the number of eggs dealt with is small, and therefore the date 

 of the height of spawning may be wrongly fixed. A similar condition 

 may be seen in the curves of spawning given by Fulton.* 



Dragoinet. The eggs of dragonet occur during the first eight months 

 of the year. One egg of dragonet and seven eggs of rockling were all the 

 eggs obtained in January, and eggs of these two species occurred each 

 month after. The largest number of eggs was obtained in June ; con- 

 siderable quantities were, however, also obtained in April and May. The 

 curve of spawning for this form does not agree with the theory advanced 

 above, but so far as this research is concerned it is the only important 

 exception. According to M'lntosh and Masterman, the dragonet spawns 

 from May to August. In Loch Fyne the spawning season begins four 

 months earlier. 



On the whole the spawning seasons which have been determined on 

 the East agree very closely with the spawning seasons in Loch Fyne, so 

 far as concerns the year 1898. The date when a species may commence 

 spawning varies from year to year, and correspondingly the last date 

 upon which the ova of that species are to be found in the sea may be 

 earlier or later from year to year. Allowing for that annual variation, 

 it is probable that with further investigation the disparity in the 

 spawning periods which is supposed to exist between the East and 

 West Coasts may be altogether eliminated or at least restricted to a few 

 species. 



* Tenth Annual Report of the Fishery Board, Part III., p. 242, pi. vi. 



