172 THE NEW AKT OF BEEEDING FISH. 



Earn, below the mouth of the Islay, upwards of 

 34,000 salmon and 30,000 grilses. The 34,000 sal- 

 mon, according to certain well-established theories, 

 must consequently have spawned in Tay and its tri- 

 butaries, some as grilse, some as salmon of inferior 

 growth, during the fence season of 1845. A suppo- 

 sition, therefore (if it deserves that doubtful name), 

 which confines the number of spawning fish on these 

 rivers to an average of 30,000, cannot be held as an 

 outrage upon truth — nay, is greatly within limits. 

 These 80,000 fish, we shall suppose, according to the 

 notions set afloat by Mr. Young and others, are 

 equally matched in respect to sex ; that is to say, 

 that out of the whole number, 15,000 are spawners, 

 and the other 15,000, milters or he-fish. To each 

 spawner I assign an average weight of 101b. A ten- 

 pound breeder, it has been ascertained, yields about 

 10,000 ova, certainly not fewer ; consequently the 

 number of ova cast, in the spawning season, on._the 

 various breeding grounds referred to, may be com- 

 puted at 150,000,000. How much of this large 

 amount of spawn are we entitled to suppose is 

 brought to life, becomes distributed over the rearing 

 grounds, attains the smolt size, and, assuming its 

 plumage, eventually finds its way into the sea or 

 firth ? " 



Mr. Stoddart computes the result of the above 

 number of ova at 20,000,000 smolts, having allowed 

 for every sort of destructive casualty. He calculates 

 that the 400,000 ova deposited in the breeding boxes 



