870 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



are sometimes walled in with masonry, sometimes they are constructed 

 of wood. Fishes intended for sale are kept in them for a few weeks or 

 months during the winter. 



The carp does not grow in the winter. Warmth alone seems to exer- 

 cise a favorable influence upon it and to promote growth. It only grows 

 in the months of May, June, July, and August, and does not appear to 

 continuedoingsoin September. The slight increase in weight which takes 

 place during the lat'er month seems to grow out of an accumulation of 

 fat which is being deposited around the entrails. In ponds which con- 

 tain plenty of food and healthy water, in an ordinary year, the growth and 

 increase of weight in the year will be represented in figures as follows : 



Per cent, 

 of growth 



May 



June 



July 



August 



September. 



Total 



If the weather in the month of May be mild and warm from the be- 

 ginning, a better growth may be expected, amounting, as in June, to 

 about 30 per centum. This month (May) is decidedly of great impor 

 tance for the growth of the fish during the current year, for, in proportion 

 as the fish has grown in the short space of one month, it will take more 

 food in the following ones as the increase of its growth and consequent 

 wants will demand. Culturists, therefore, consider the month of May 

 as being the most important of the whole period of the carp's growth. 

 The above-given calculations, of course, are limited to ponds in which 

 no artificial feeding is resorted to, but in which there is sufficient food 

 by reason of the good quality of the water and soil which produces it. 



In small ponds, situated in parks or gardens, which possess favorable 

 soil and river-water, the increase of weight will be even a little greater 

 if feeding is had recourse to, for such small ponds (covering only half 

 an acre) cannot produce sufficient food themselves. On the whole, feeding 

 is a make-shift, as will be seen presently, and which in very large ponds 

 of more than from 20 to 1,000 acres should not be made use of. 



The above calculations are only admissible for Central Europe, from 

 the Adriatic to the Baltic and the North Sea ; in countries further north, 

 as in Sweden, the growth of the carp is less, as, on the contrary, in more 

 southern countries than Central Europe, for instance in lUyria, Dalma- 

 tia. Southern Italy, Southern Spain, and partly, also. Southern France, 

 the result is more favorable still. There a milder and warmer climate, 

 an early spring, a very warm summer and autumn, and a late winter 

 which, in addition, is mild and short, combine to exercise a favorable 

 influence upon the thriving condition of the fishes. 



