THE HISTORY OF FISH-CULTURE. 477 



Apart from this loss, they succeeded very well, and I have obtained in 

 tliree years, out of the fish, in this manner, a crop of three to four hun- 

 dred trouts a year, of three to four years of age, and of which the largest 

 weighed three-quarters of a pound." M. Vogt, in a letter recently pub- 

 lished, which reproduces this passage of M. Knoche, informs us at the 

 same time that a decree of the government of J^eufchatel, issued in 

 1842, gave complete instructions to the fishermen as to the method of 

 artificially fecundating the eggs of fish. 



Some experiments have also been made in England and Scotland. 

 After having studied during several years the manner in which the 

 salmon spawn naturally, Mr. John Shaw* attempted to combine the 

 conditions which appeared most essential* in some preserves which he 

 caused to be made near the river Nith. These reservoirs were only 

 two feet in depth, and spread with a thick bed of gravel. They were 

 fed directly by the water of a spring, which abounded with the larvre of 

 insects. A close grating was placed before tlie conduits, by which the 

 surplus of this water had to How out to gain the river. These disposi- 

 tions once made, Mr. Shaw fecundated the eggs just below the point 

 where the water fell into his basins, and left them to develop at the 

 same spot. This plan succeeded, and he was' able to bring up a certain 

 number of young salmon during two years, and even more. He took 

 advantage of them to make observations upon their growth and change 

 of color. At the age of six mouths the young salmon had a length of 

 two inches; of a year, three inches and three-quarters^ of sixteen 

 months, six inches; and of two years, six inches and a half. At this 

 last period, when they had put on the livery of emigration, aud when they 

 are called in Great Britain by the name of parr, the milt of the males 

 had arrived at a sufficient state of maturity to be able to fecundate the 

 eggs of adult females. We owe also to Mr. Shaw, as well as to Mr. 

 Andrew Youngt and Dr. Knox, our increased knowledge of various par- 

 ticulars relative to the monogamy of salmons, aud to the maneuvres 

 which the female ])erforms on the spawning place, but these researches 

 do not appear to have had any practical result worthy of attention. 



An engineer of Hammersmith, named Gottlieb Boccius, published in 

 1848 a short treatise on the management of fish in rivers and streams. 

 He extols in it the method of artificial fecundation, but without produc- 

 ing any positive fact to prove that he himself experimented with suc- 

 cess. | Since that time he has assured Mr. Milne-Edwards that he had 



* Transactions of the Royal Society of Edinburgh, vol. xiv, p. 547, 1840. 



t Natural History of tiie Salmon, Wick, 1848. 



i lu a previous work by the same author, (A Treatise on the mauagemeut of Fresh- 

 water Fish, with a view to makiug them a source of inolit to lauded' proprietors, by 

 Gottleib Bubocci London, John Van Voorst, Pateruoster Row, 1841,) there are directions, 

 on page 19 for the propagation of trout by the method used bj^ Lund, of confining a 

 male and female in a box sunk in the stream. 



It is very evident from this work that the author at the time of preparing his manuscript 

 makes no claim to a knowledge of artificial fecundation. 



