58 WOIIK IX THE HATCHING-HOUSE. 



render visible the paths of the currents, small whirlpools will be 

 noticed descending over the apex of each mass, while from the 

 base the water radiates in a thin, swiftly-moving cloud. 



On closer inspection it will be noticed the alevins are lying 

 with their heads approximately towards the apex, and their paired 

 pectoral fins working with remarkable rapidity ; thus, instead of 

 those lowest in the mass being in danger of suffocation, they really 

 receive the strongest water currents. The mass is, in fact, a 

 gigantic co-operative breathing association. 



Very different is the fate of the unfortunate who finds a 

 refuge beneath the sheet of glass so frequently used in the early 

 days of trout- hatching to preserve the eggs from fungus. In a 

 very few hours a pale lifeless form marks the grave of the suicide. 

 Charred wood has abolished the necessity for linings of any sort, 

 but the general public still delight in providing all sorts of death- 

 traps, under the name of shelters. 



After the fry have herded together for a few weeks, more or 

 less, according to the temperature of the water, they are seized 

 with a roaming and inquisitive spirit. At this stage the use of 

 flannel in fixing the safety-screen becomes apparent. But it must 

 be new flannel ; old sodden stuff is certainly water-tight, but still 

 they manage to burrow beneath it, and, although they cannot 

 pass through, will manage to suffocate themselves in. considerable 

 numbers. New flannel is seldom water-tight, but this is of no 

 consequence. Whether the fine hairs annoy them, or whether in- 

 herited instinct teaches them to dislike the manufactured product, 

 of the animal whose periodic washings have so frequently nauseated 

 their ancestors, I know not ; but it is nevertheless a fact that 

 the alevins will test every joint in the box, but leave the flannel - 

 protected joints of the safety-screen alone. 



The only attention newly hatched alevins require is as to the 

 strength of the current passing through the safety-screen. If the 

 water is kept shallow, and the current equivalent to 2 gallons 

 per minute through the ordinary Howietoun hatching-box, there 

 is some danger, during the first few hours of the hatch, of so many 

 of the holes of the perforated zinc of the safety-screen becoming 



