APPENDIX. 245 



Twelve acres of water divided into three parts would allow 

 a splendid series of ponds — the first to be three acres in 

 extent, the second an acre more, and the third to be five 

 acres; and here it may be again observed that, with water 

 as with land, a given space can only yield a given amount 

 of produce, therefore the ponds must not be overstocked 

 with brood. Two hundred carp, twenty tench, and twenty 

 jack per acre is an ample stock to begin breeding with. A 

 very profitable annual return would be obtained from these 

 twelve acres of water ; and, as many country gentlemen 

 have even larger sheets than twelve acres, I recommend 

 this plan of stocking them with carp to their attention. 

 There is only the expense of construction to look to, as an 

 under-keeper or gardener could do all that was necessary in 

 looking after the fish. A gentleman having a large estate in 

 Saxony, on which were situated no less than twenty ponds, 

 some of them as large as twenty-seven acres, found that 

 his stock of fish added greatly to his income. Some of the 

 carp weighed fifty pounds each, and upon the occasion of 

 draining one of his ponds, a supply of fish weighing five 

 thousand ponds was taken out ; and for good carp it would 

 be no exaggeration to say that six pence per pound weight 

 could easily be obtained, which, for a quantity like that 

 of this Saxon gentleman, would amount to the sum of £125 

 sterling. 



IV. 



DISCOVERY OF ARTIFICIAL FECUNDATION BY JACOBI.* 



In 1763, Jacobi, a lieutenant in the small principality 

 of Lippe-Detmoldt, first announced, in the pages of the 

 " Hannover Magazin," a periodical published in the town 



* From Agricultural Eeport, 1866. By Theodore Gill, M. D. 

 21* 



