74 



THE SEA-TROUT 



several rows here and there. As the eggs occupied 78 rows of the 90 

 in the grille, there were apparently altogether 2,028, but allowing 52 

 for any possibly unshed and for loose eggs here and there on the grille, 

 we get a total of 2,080 eggs for this fish of 2j lb. in weight. This 

 gives us (with one egg out) exactly 924 eggs per pound weight of parent. 



Assuming that these eggs, as in the case of the salmon eggs men- 

 tioned above, weighed 260 to the ounce, the mass of eggs in this sea- 

 trout weighed exactly half-a-pound. Of course 924 eggs is greatly in 

 excess of the usual allowance of 800, but this was an exceptionally fine 

 specimen fish, caught too before a single egg had been extruded. 



Most of our knowledge regarding the development of the eggs of 

 salmon, sea-trout and trout has been acquired in hatcheries, but there is 

 no reason to assume that such development differs in any important 

 respect from the development of the ova under natural conditions. 

 Perhaps hatchery conditions may accelerate matters to some little 

 extent because in nature development is often retarded by recurring 

 periods of low temperature, a disadvantage which the hatchery eggs 

 escape as the temperature within doors is kept at a uniform level. But 

 any difference is immaterial to the present purpose. 



One can imagine, then, that in the fertilised egg, hidden away in 

 some dark recess of the gravel, with the temperature of the water 

 varying between 40° and 45° F., the embryo fish will, after thirty days 

 or so, have so far developed that its eyes will have become visible as 

 two little dark specks through the semi-transparent covering of the 

 egg. At this stage, when the eggs are technically called " eyed ova," 

 they may with impunity be subjected to a good deal of handling and 

 disturbance, and it is when in this state that the eggs of trout are usually 

 transferred from hatcheries to purchasers for the purpose of stockino- 

 and re-stocking waters. 



With things going propitiously, in other 60 days, or in about 90 

 days altogether (trout taking a total of 70 days and salmon 120 days) 



