THE SALMON 37 



emarginate. In grilse the maxillary extends to, or 

 nearly to, the vertical from the posterior edge of the 

 eye, or sometimes slightly beyond, whilst in Sea- 

 trout of this size the maxillary reaches back well 

 beyond the eye. 



Grilse come in from the open sea and appear 

 on the coast in large companies, and in the summer 

 many of them ascend the rivers from which they 

 came, to spawn in the autumn and return to the 

 sea as grilse kelts in the winter or early spring; on 

 the other hand a number of them do not enter fresh 

 water until the winter or spring, when they are 

 nearly four years old and are known as small spring 

 Salmon ; these are very similar to grilse in size 

 and appearance, but do not spawn until the following 

 season. Further, it seems that quite a number of 

 fish not only pass through the grilse stage in the 

 sea, but may stay there until they attain a 

 considerable weight, entering fresh water for the 

 first time as " maiden " Salmon when they are four, 

 five, or even six years old. 



Salmon which have spawned exhibit just as great 

 differences in the time which elapses before they 

 return to the rivers ; some spawn in successive 

 seasons and the kelts pass only a few months in 

 the sea before they go back again ; others may miss 

 a year, whilst others still may let two years or more 

 go by before they again feel impelled to ascend the 

 rivers in order to reproduce their kind. 



We are now able to see that Salmon of the same 

 weight may be of very different ages ; annual 

 spawners increase in weight very slowly, for the 

 time spent in the sea sometimes scarcely does more 

 than make good the loss entailed by the stay in 



