192 How to obtain it. 



breath. At this time of their existence they are helpless creatures 

 indeed. 



When hatched naturally in a brook or in an artificial ova 

 bed, the case is very different. They are then amongst the gravel, 

 which is the protector which Iiature gives them from their enemies. 

 The hatching box is perfectly clean, and there is, or should be, 

 nothing which they can get under. They will very soon begin to 

 make up for this by getting under each other, and in their efforts 

 to do so will collect in dense masses which have been likened to 

 swarms of bees. In fish-cultural language they begin to " pack," 

 and there is no more healthy sign than to see all the alevins in a 

 box well "packed." 



Many years ago the great idea was to provide some artificial 

 "hide" or place for shelter for them, and many devices were 

 thought of, but all proved to be great failures. The effect of 

 placing a stone or other object in a hatching tank for the fish to 

 get under is to provide a place where there is no current, and 

 which instead of being beneficial will only prove a " death trap " 

 to a large number of the alevins. By leaving them alone, 

 however, a very different result is obtained. Some of them begin 

 to feel an instinctive desire to get into a place where the water is 

 constantly changing, and having found out by following up the 

 current the exact point which best suits them they remain there, 

 and others gather to them, and before long they will all be 

 densely packed with their heads turned the same way, and their 

 noses pointed downwards. 



The sight of from ten to fifteen thousand fish in such close 

 proximity to each other might lead one to suppose that many 

 would be suffocated, but this never proves to be the case. They 

 are perfectly safe as long as they remain packed, but should they 

 begin to scatter at too early a stage of their existence, then look 

 out for mischief. Whilst packed they are just in that particular 

 part of the current which suits them best, and as long as they 

 remain there they will take no harm. I am, of course, assuming 

 that the water supply will in no way be tampered with just at this 

 time. A slight disarrangement of the current will cause the little 

 fish to move, or, as one of my men used to put it, to " shift their 

 quarters." And this is better avoided. Too much light is also 



