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Prof. J. C. Ewart. On the Natural and [Mar. 27, 



that they spawn near the surface, this latter being the favourite 

 theory of Dutch fishermen. 



In the preliminary report of last autumn's work already referred 

 to, we give it as our opinion that "The spawn once ripe they congre- 

 gate at the bottom, the females depositing their roe on the rocks and 

 sea- weeds, to which it at once firmly adheres, and the males fertilising 

 it with their milt." 



But it will be observed we did not venture an opinion as to how the 

 spawn was deposited, or how it was fertilised. 



Having secured at Ballantrae a number of live herring, we 

 selected the largest and ripest males and females, and placed them 

 in a large wooden tank, into which a number of stones and a quantity 

 of sea- weed had been previously introduced. After the fish had been 

 about two hours in this tank we examined the stones and sea-weed. 

 Although a few eggs were attached to both stones and sea- weed, it 

 was quite evident that they had not been deposited in the same 

 way as those found on the stones dredged on the previous day, but 

 the presence of the eggs indicated that we had secured ripe females. 

 We were not surprised that only a few isolated eggs were found on 

 the stones, because the fish had been disturbed every few minutes by 

 the water poured into the tank in order to keep them sufficiently cool 

 and provided with an abundant supply of oxygen. Having arranged 

 a tent-like covering over the tank, so as to inclose the fish in a dark 

 chamber, we tried the effect of throwing instantaneous flashes of 

 light on the surface of the water, but as far as could be observed this 

 produced no impression whatever, they neither sought the light nor 

 avoided it, neither did they seem in auy way startled, however 

 suddenly it was directed across their path. This led us to believe 

 that their natural movements would not be seriously interfered with 

 when introduced into the tanks at the Rothesay Aquarium. 



On reaching Rothesay the hatching boxes and live herring were at 

 once transferred from the " Jackal " to the tanks, a tank into which 

 comparatively little light entered being selected for the ripest and 

 most vigorous herring. In about half an hour after they were intro- 

 duced I noticed a large full herring moving slowly about the bottom 

 of one of the tanks, and thinking it had suffered during the journey, 

 I introduced a landing-net, in order to remove it, when, much to my 

 surprise, it darted to the opposite end of the tank. Having, however, 

 without much difficulty, secured the herring, and having ascertained 

 it was a perfectly ripe female, it was set at once free. In a few 

 minutes I noticed her moving slowly quite close to the bottom of the 

 tank, with four other fish making circles around her at some distance 

 from the bottom. Appearing satisfied with some stones which she 

 had been examining, she halted over them, and remained stationary 

 for a few minutes about half an inch from their surface, the tail 



