1 62 THE SEA-TROUT 



streams of Loch Lomond. I watched one female of about 6 lb. weight 

 within five paces of me. Before turning on her side she raised her 

 head and opened her mouth wide, then, almost doubling up, she lashed 

 out vigorously with her tail, and with a sort of burrowing motion 

 sideways scattered the gravel and raised a cloud of sediment which 

 almost concealed the male fish swinging to and fro in the current behind 

 her. After repeating the burrowing action several times she would 

 rest, then heading a little upstream she would begin again, the male 

 always being in attendance. The cleansing of the upturned gravel 

 from all sediment makes the redd easily distinguishable in the channel. 



I am not certain that the female makes a hollow — I have seen it 

 described as a rudimentary nest — of set purpose, but a hollow is at any 

 rate the outcome of her spasmodic actions, and I imagine that a 

 considerable proportion of the ova finds a resting-place in the loosened 

 gravel behind her, to be effectively covered as the upstream gravel 

 is in turn displaced. 



I was at some pains to find out how the stream acted on the ova. 

 From the floating leaves I gauged that the current ran at the rate of 

 nearly three miles an hour, and into a similar stream at more conve- 

 nience later I flung a quantity of ova. I was greatly struck with the 

 speed with which the eggs found each a resting place. One had the 

 idea that they would be carried initially a considerable distance down 

 stream, but this is not the case ; they find bottom almost immediately. 

 The reason, I take it, is that the eggs are compact and materially heavier 

 than water and so sink at once. Then it is surprising to see how 

 effectual an " eddy " is caused by the slightest inequality of the bottom. 

 The surface may appear to be even-flowing, but under the lee of the 

 smallest pebble the water pauses for an instant, and behind every stone 

 an egg may come to rest. Once it is at rest it is also matter for surprise 

 how quickly the egg disappears from view. Its semi-transparency 

 makes it a very inconspicuous object in the water, but I think its 



