124 FISH HATCHING. 



for concealment ; many of them stupid 

 creatures even getting their heads so far 

 under these stones that they could not get 

 them out again, and there they remained till 

 next morning, when I found them literally 

 drowned, and with their tails projecting up- 

 wards, like the tails of dogs and cats we see 

 drowned in shallow water by that most simple 

 but effective apparatus, a stone and a cord. 



I concluded from the actions of these fish 

 that light was unpleasant to them, and that 

 they wanted hiding-places. I recollected, 

 moreover, that one generally sees swarms of 

 such small fish near bridges. I therefore got 

 some bits of zinc and some stones, and built 

 miniature bridges in the tanks. I touched 

 up the salmon one by one, and three out of 

 four of them swam away under the bridges in 



