Fishes. 2195 



wheat is in blossom, which will pretty well indicate the temperature of the water as 

 well as the air. These fish spawn near the surface, and this accounts in part for the 

 difficulty of breeding them in rivers and streams ; though, when bred in ponds, and 

 afterwards turned into rivers, they thrive fast and well, and are better as food. And 

 here, while I am on the subject of carp, I may as well mention that the gold carp, a 

 native of the Eastern World, cannot breed or spawn under a temperature of from 70° 

 to 80°, but at that they will breed luxuriantly : proper care, however, must be taken, 

 or they will devour every particle of spawn they have deposited. An instance of this 

 voracity I have from a gentleman who kept some of these fish in a reservoir in his hot- 

 house, but lost his brood regularly from this cause, till he placed some water-plants in 

 the reservoir last year, and thus secured the stock. Few persons are aware of the 

 cause of the death of these beautiful little fish when kept in the globular glasses, even 

 where much care is bestowed upon them. It is simply this, — they become heavy in 

 spawn, and not being able to rid themselves of the egg, for want of the assistance 

 which plants afford in the act of parturition, inflammatory action takes place in the 

 ovarium, mortification ensues, and death is the consequence." — p. 12. 



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" As regards salmon, if I am rightly informed by a gentleman at Gloucester, who 

 is a proprietor of twelve miles of the river Severn, the grilse spawns in September and 

 October ; the salmon in October, November and December. The young fish issue 

 from the egg in from 100 to 120 days, according as the warmth of the water may have 

 varied, which at that time of the year, from cold, rain or snow, it frequently does ; the 

 process of incubation being retarded in proportion to the effects produced by the nitrous 

 quality of snow-water, which reduces the temperature from 55° to 30°, and that in a 

 few hours ; and when a large mass of snow falls into a spring-stream, it acts like salt 

 combined with snow, and freezes all before it. Oyster-beds for miles are sometimes 

 from this cause totally destroyed in one night ; for when this occurs all fish retire to 

 the deeps. Some streams, from this, in conjunction with other causes, freeze upwards 

 from their very beds in the shallows, and it is there where most fish prefer to spawn : 

 so that every egg is directly destroyed ; but, fortunately, this extreme case is not of 

 frequent occurrence, although I have observed it in more instances than one. The 

 ice forms on the bed of the stream, and rises upwards to the surface as the water reco- 

 vers its original temperature. There are parts of the Colne where this can be observed. 

 As grilse spawn so much earlier than salmon, being maiden fish, it follows that the 

 produce of their spawn is much earlier ready for migration, and begin to run in April, 

 when they are about fifteen months old. I have omitted to mention, in its proper 

 place, the interesting fact, that the shell of the young fry of salmon adheres to the 

 umbilical cord for nearly a calendar month, which brings the fish to 130 days from 

 the deposit of the egg before he can hunt for his food, and the smolt is beyond a year- 

 ling before he is strong enough to take to the salt water ; and when this change is 

 made, he bids adieu to fresh-water feeding for ever. A salmon or a grilse, returning 

 to its native river to spawn, feeds no more on what was formerly its food, though it 

 sports with flies, and will now and then take a minnow or a lobworm. No sort of food 

 is ever found in the maw of the salmon when captured in fresh water; but when taken 

 at the mouths of rivers, or on the coast making towards them, the remains of small 

 fry are frequently found among the contents of the stomach. The salmon and grilse, 

 too, when taken at the mouth of a river, are of different flesh and flavour to those 

 taken up-stream, the former being firm, brittle of flesh, and of large flake ; but when 



