OF THE SALMON. 65 



placed there by man, their very worst and inveterate 

 enemy. That and many other siclike of all shapes 

 and contrivances they have to encounter between the 

 sea and their native river ; and it is very few indeed 

 that reach there, for between the sea and it the cater- 

 pillar have devoured what the cankerworm left. The 

 few grilses that are fortunate enough to reach the 

 river spawn the same year along with the salmon ; in 

 general they are the first who occupy the breeding 

 banks, and we see them there in pairs as regular as 

 the salmon are ; but we also see that a female salmon 

 has no objection to work along with a male grilse in 

 the event of her not being fortunate enough to find 

 one of her own age and size. The ova of a grilse of 

 five pounds weight is about one-fourth of a salmon of 

 twenty pounds, for they spawn a thousand ova for 

 each pound they weigh, that is, a salmon of twenty 

 pounds will spawn twenty thousand grains of seed, 

 and a grilse of five pounds will spawn five thousand 

 grains. The ova of grilses, according to their num- 

 ber, are equal to those of salmon, both in regard of 

 time in hatching and also in producing as good fry, 

 for we find them hatch in the same time, and the fry 

 continue equally large in all their stages. There 

 must be the same difference in the quantity of the 

 milt of the grilse and salmon as there is in the ova ; 

 therefore, whether the milt of a grilse be sufficient to 

 impregnate the whole ova of a female salmon is a 

 question yet to be solved ; at all events we find that 

 the milt of a male is all exhausted during the time 

 that the female is laying the eggs : this happens to 

 both salmon and grilses, and therefore, as we are 

 aware that nature has formed nothing in vain, we 

 must conclude that the whole quantity of milt in 

 the one is necessary for the whole ova in the other, 

 and in that case we are led to believe that when a 

 F 



