463 Linnaan Society. 



stream in Yorkshire," which appeared in the * Durham Advertiser * 

 for April 16th in the present year, under the signature of Isaac 

 Fisher, together with an unpublished letter from the same gentleman 

 in answer to a request from Mr. Hogg for further information ; and 

 added some observations of his own upon the same subject. From 

 the letter published in the ' Durham Advertiser,' it appeared that 

 Mr. Richard Harrison of Richmond had procured from the river 

 Tees a brood of spawn, taken and milted from the living fish, which 

 he deposited on the 29th of December last in a small tributary of the 

 river Swale. On the 21st of March two of the ova were brought to 

 the house of Mr. Fisher and placed in a vessel of water, the foetal 

 signs were clearly distinguished, and in two days more they became 

 living fish ; he is consequently satisfied that the salmon is now 

 restored to the river Swale, from which it has of late years been 

 banished. Tn answer to Mr. Hogg's inquiries, Mr. Fisher states 

 further that the ova and milt were obtained in the Tees, according 

 to the directions given by Boccius, Shaw, and " Ephemera," in his 

 *Book of the Salmon.' They were taken from three female and 

 two male fishes on the night of the 27th of December, and not depo- 

 sited in the gravel of a small rivulet until the 29th of the same 

 month. Part of the ova were also placed in a gravel bed in the 

 river Swale ; but of the result of this part of the experiment Mr. 

 Fisher has no present information. In one part the ova were 

 placed too deep in the gravel, and on examination were found to be 

 addled ; while there is every reason to believe that those which were 

 placed about 3 inches in the gravel have all been hatched. A live 

 fish brought from the spawning- bed leaped out of the vessel in which 

 it was kept and speedily died, and the two mentioned in the pub- 

 lished letter also died in the course of about ten days, probably in 

 consequence of the disturbance to which they were exposed from the 

 curiosity of those who came to see them, and who were desirous of 

 observing the extreme velocity with which they moved round the 

 vessel, even while the vitelline bag was still attached to the abdo- 

 men. The spawning-bed was formed in a small run of spring- water 

 which is never affected by the frost ; it was cleared of minnows, 

 young trout, &c., and at each end of a space of about twenty yards, 

 whins were placed of a good height, kept down with stones, to pre- 

 vent the entrance into it of other fish. After some observations re- 

 specting minnows, Mr. Fisher adds : " We have proved the fact that 

 the river Swale may be again stocked with salmon, provided we can 

 make arrangements with the proprietor of a mill-wear, twenty-five 

 miles from this place, to let the fish, on coming up from the sea, 

 have 'free-gap' from time to time." 



On these letters Mr. Hogg observes, that it seems to him there 

 can be little (if any) doubt that, with the precautions indicated, a 

 vast increase of salmon might be obtained, and a sure and valuable 

 source of wealth be secured in many suitable streams in which no 

 salmon are at present found ; and the same artificial process of 

 breeding might likewise be applied to trout with an equally advan- 

 tageous result. He suggests that the breeding might also be carried 



