TROUT WATERS AND CARP WATERS 



handled in this way; inert, and heaped up almost 

 one on top of the other, they can spend whole months 

 without moving or eating. 



A hibernation of this sort, which is accompanied 

 by a partial stoppage of vital phenomena, has certain 

 definite results. The trout grows in mid-winter, 

 though not very much, but the carp does not grow 

 at all. Its growth stops with the first frost of autumn, 

 and does not begin again until the spring. For four, 

 five, even six months, varying according to year and 

 locality, the carp remains stationary, not growing or 

 becoming any bigger, even losing slightly. The real 

 growth, the increase in weight and size, takes place 

 only during the warm summer months, and the higher 

 the temperature of the water, the better, quicker, and 

 more satisfactory it is. This growth is not regular; 

 it has its ups and downs; it is not like that of land 

 creatures, such as we see it in stables and poultry 

 farms, where growth goes on regularly and with 

 continuity. The carp give up to it only a part of their 

 existence; it is subordinate to the seasons. So we 

 understand the reason why carp breeders count the 

 age of their stock by summers and not by years. The 

 carp is a product of summer, like the fruit of our 

 trees and the grain of our harvests. It lives and grows 

 under the beneficent influence of a favourable seasonal 

 temperature. 



This thermic influence of the environment upon the 

 living world of the waters is direct and considerable. 

 Its result is an adding to the caloric energy of the 

 combustion involved in respiration; and is con- 

 sequently always of great importance. In spite of 

 all divergences in the constitution and needs of the 

 creature, and in external circumstances, it provides 

 the organism with the means of accomplishing the 

 functions which enable it to survive. It does so all 

 the more because it is, in this respect, in a more 

 precarious and dependent position. 

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