468 Fishes. 



three feet higher than the bed of the stream. From the 

 middle of December to the end of January the Trout is 

 in full spawning operation ; when the fish deposit their 

 eggs in the hollow, and afterwards work the gravel over 

 them to the depth of about three inches. If the tem- 

 perature of the water is not altered during the period of 

 incubation, the young make their appearance on the 

 fiftieth day; never earlier, frequently later. Nature 

 has endowed the young fry with so much instinct of 

 self-preservation, that for many days they keep under 

 the gravel, and it is curious to see the shoal hiding 

 together under large stones to protect themselves from 

 danger : this they continue to do until the eggshell, in 

 which they remain partially enveloped, falls off from 

 their delicate frames. This shell, which adheres to them 

 for fourteen days, contains a proportion of fluid necessary 

 for their support during this period of helplessness. 

 After this they resort to the shallows and scours to avoid 

 the larger fish, where they remain solitary for a year, 

 during which time, in good keep, they attain the weight 

 of three to four ounces ; the second year, eight to ten 

 ounces ; after which they begin to breed. A fish, like 

 every animal, becomes fat when it has abundance of 

 food with little or no exertion ; so that the growth is 

 entirely regulated by the relative proportion of food and 

 labour. I have observed this difference in the same 

 brood of Trout, artificially bred -upon my system : the 

 one brood being placed in water well supplied with 

 food, the other in a spring-stream where little food 

 existed ; the former, at ten months old, were four inches 

 long, and three and a half ounces in weight, while the 

 latter were only an inch and a half long, and less than 

 an ounce in weight. Although Trout are not migratory, 

 yet, when they become large, they run up stream to 

 purer water.- The small Trout are carried down the 

 stream against their habit, by the flushes of water or 

 floods during the autumn months, being unable to stem 

 the thickened torrent, which fills their gills with allu- 

 vial deposit, and hinders their respiration, whence they 

 become weak and sickly. In this state of water all fish 

 sicken more or less, and it destroys vast numbers in the 



