THE AETIPICIAL INCUBATION OF OVA. 65 



spawn rather does good .than harm to the stream, 

 they are not always to be relied upon to let the pisci- 

 culturist know the proper time to come for the spawn. 

 I have been deceived so often in this way, and had 

 so many fruitless and vexatious journeys, from this 

 jealousy of keepers, that I warn my brother pisci- 

 culturists to keep a sharp eye upon them. Ti'out 

 and salmon appear on the beds a week or so before 

 they spawn, at any time from November to March. 

 The season lasts some weeks, but it must always be 

 borne in mind that the earlier spawners are by far the 

 best, not only as yielding stronger and more advanced 

 fry for the next season, but as yielding even a larger 

 per centage of fry. If, therefore, the keeper be 

 ordered to send word as soon as the fish come on 

 the shallows, and the pisciculturist goes a week or 

 ten days after they are first seen to come up, he 

 will be in good time. This is not the case, however, 

 with greyling; they are so short a time over their 

 spawning, and in March and April, when they are 

 thus engaged, the netting is so likely to be inter- 

 rupted by floods, that no opportunity, not a day, 

 nor an hour, should be lost ; very many times have 

 I known a delay of a day cost the pisciculturist 

 his stock of ova for the year. As soon as the large 

 greyling are observed to .come on the shallows the 



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