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A'ppcndices to Fifth Annual Report 



APPENDIX F.— No. IV. 



ON THE ARTIFICIAL HATCHING AND HEARING OF SEA 

 FISH. By J. C. Ewart, M.D. 



With Plates VII., VIII, IX. and X. 



The publication last autumn of The History of Howietoun* marks an epoch 

 in the history of fish culture. It affords abundant proof that the Salmonidaa 

 at least can be bred and reared in confinement as successfully as any of 

 the smaller domestic animals, and that fish culture, notwithstanding all 

 the reverses it has suffered through the misplaced zeal and energy of its 

 many would-be advocates, has a great future before it, not only in re- 

 stocking our own rivers and lakes, but also in peopling the waters of all 

 countries where the conditions are favourable to the development and 

 growth of the Salmonidae and other valuable food fishes. 



Although the fame of the Howietoun fishery has long been world-wide, 

 few, before its history appeared, knew of the magnificent scale on which it 

 had been constructed, or of the care with which everything had been 

 designed so as to minister to the great object in view, viz., the production of 

 the largest possible number of strong active fry, not the hatching of the 

 largest possible nnmber of eggs. As an indication of the hatching powers 

 of Howietoun, it may be mentioned about 6,000,000 of the large eggs of 

 the Salmonidse may be laid down in the hatching boxes in a single 

 season. But the rearing ponds are equally extensive, for in addition to 

 accommodating a sufficient number of full-grown artificially reared fish 

 (over six years old) to produce 4,000,000 eggs, they can receive annually 

 800,000 fry, to be reared for breeding purposes, and a large number to be 

 afterwards sold as one or two year old fish. In a single season 2,000,000 

 incubated eggs (almost ready to hatch) may be despatched from the 

 fishery, and in addition 450,000 fry, 85,000 yearlings, and 12,000 two- 

 year olds. 



The Howietoun eggs and young fish find their way into all the more 

 important waters in Britain, many cross the Channel to the Continent, 

 and last winter 600.000 salmon eggs (sent to the fishery from the Tweed, 

 Forth, and Tay to be partly incubated) were despatched under the 

 personal superintendence of Sir James Maitland to New Zealand. 



Further, no fewer than seven ponds at Howietoun are, in the meantime, 

 devoted to hybridisation experiments, under the direction of Sir James 

 Maitland and Dr Francis Day, — the experimental work alone representing 

 an outlay of five or six hundred pounds annually. 



Fish culture at Howietoun has been reduced to a science. Every step 

 in the process, from the impregnation of the eggs to the rearing of the 

 mature fish, has been thoroughly mastered and systematised. So careful 

 have the observations been from first to last, that it is now possible to 

 produce, within certain limits, considerable modifications in the time at 

 which the eggs mature and hatch, and in the rate of growth of both the 

 fry and the older fish ; and further, many hybrids have been bred, the 



* The History of Howietoun, by Sir J. Ramsay Gibson Maitland, Bart. Stirling, 

 1887. 



