1024 REPOET OF COMMISSIONER OF FISH AND FISHERIES. [16] 



or tliat a part of the fish in one pond do not reacli the same weight as 

 the other fish in that pond. The canse of such uneven growth must 

 generally be found in the circumstance that the. fish with which the 

 pond was stocked differed much in weight. Thus a difference of 50 

 grams, which would hardly be noticed with the naked eye, would, for 

 example, in two-year old fish, which generally grow 150 per cent., result 

 in a difference of 125 grams. For instance, if fish had been placed in 

 the pond weighing from 250 to 300 grams, the former would reach a 

 weight of G25 and the latter of 725 grams, showing a difference easily 

 recognized with the naked eye. In fish, whose power to grow differs 

 very much, this difference will be still more easily discerned. 



Such irregularities should be corrected at once, as otherwise they 

 may injure the system for years. In a well-organized and rationally- 

 conducted i)iscicultural establishment it will not be possible to remedy 

 the evil by diminishing the number of fish in each pond, because it is 

 the object to raise every year an equal number of fish of equal weight, 

 and therefore under otherwise equal conditions the number of fish in 

 the different ponds must remain the same. 



There are, therefore, only two ways, either to raise the young fry in 

 ponds, outside of the farm proper, such as I have recommended in my 

 manual, and which I have designated as "ponds at disposal" {disponi- 

 hle Teiclie) (See p. 308, &c.), or to resort to artificial feeding. 



It is self evident that, for this purpose, the fish should be placed in 

 one or several ponds without mixing them with other fish, either greater 

 or smaller. If, for instance, one has in a growing-pond of the first class 

 (calculated to raise, during a period of four years, fish of 1,260 grams 

 weight) some fish which have not reached the necessary weight of 2G0 

 grams, but perhaps only 100 grams, the most rational plan would be — 

 in case the natural method indicated above cannot be followed — to feed 

 the fish, which have been retarded in their growth, so much during the 

 following year as to cause them to reach the weight of 625 grams 

 necessary for their transfer into another pond. 



If, thereby, contrary to intention, a greater weight than the normal 

 weight is obtained, this will, of course, do no harm whatever. Only 

 one should then take the precaution to follow one of the fundamental 

 principles of fish culture, viz, to keep fish of the same weight together 

 and see to it that they do not mingle with those of different weight, as, 

 in that case, the larger fish might injure the smaller ones; the only re- 

 sult will be that one will have some fi-^h which exceed the normal 

 weight, which, however, will be an advantage, as it will increase the 

 price of such fish, and will therefore add to the income of the piscicul- 

 turist. As a general rule a minimum weight is agreed upon in the con- 

 tracts for the sale of fish, and the buyer will generally be pleased to see 

 some of the fish exceed this weight. In case the difference between the 

 weight obtained and the normal weight is not very great; if, c. g., one 

 has, in a feeding-pond of the first class, fish weighing between 200 and 



