76 DESPATCHING LIVE TEOUT. 



to tell by any test of taste or smell whether they are suitable or 

 very much the reverse. 



There is one small stream near Craigend, the Auchenbowie 

 burn, which rises in a bog called the Black Dam, which is not 

 unsuited for growing yearlings ; but if travelling tanks are filled 

 with it these trout cannot be conveyed for more than half an hour 

 without great loss ; and the fish from the ponds at Craigend are 

 now always transferred to Howietoun in tanks which have been 

 filled with the pure water from the Loch Coulter burn. I am 

 unable to give any reason, but many seasons' experience has 

 proved that burn-water, although unpolluted, may be absolutely 

 fatal to fish transported in tanks filled with it. To enable trout 

 to travel in tanks without change of water, all that is necessary 

 is to prevent the fish themselves contaminating the water, and to 

 so construct the tank that the oxygen extracted by the fish is 

 replaced by the splash of the water. Many very ingenious con- 

 trivances have been made : electrical air-pumps, foot bellows, 

 rotatory bellows, false bottoms, and circulating tanks. Some of 

 these answered the purpose well, others very much the reverse ; 

 but none of them were sufficiently practicable to enable trout to 

 be transported on a commerical scale ; and in nearly every case 

 the inventor ignored the anatomical fact that trout or salmon 

 cannot respire freely if lying against a curve. All that is neces- 

 sary to demonstrate this is to lay a dead fish in an oval fish- 

 carrier or round wash-tub. If the fish is as long as the radius of 

 the curve one gill-cover will be tightly closed, and the other, 

 though slightly open, will be pressed against the side. It is all 

 very well to say the fish might lie in the middle, but, if the 

 tank is sufficiently stocked, a large number of the trout must lie 

 against the side ; and if only a few fish are placed in the carrier, 

 for some reason probably because they are afraid of knocking 

 their noses they will not remain in the centre, but will probably 

 take up their position against the side at right angles to the 

 radius. From this it follows that tanks for the conveyance of 

 large trout must be rectangular, although those for carrying 

 yearlings are more conveniently made round, their length bearing 



