GRILSE 51 
grilse as compared with salmon which are caught in 
many localities on our coasts, and to the fact that 
grilse appear to affect some localities more than 
others. Major Traherne tells us* that in the 
Hampshire Avon and the Ogmore in Glamorgan- 
shire grilse are absent, although adult salmon are to 
be found. I believe, as a matter of fact, this state- 
ment is open to question. It seems undoubtedly 
true that grilse, although abundant on the coast, may 
not enter certain rivers as salmon do. That, in 
other words, the proportion of grilse to salmon on 
the coast is a very different thing from the proportion 
of grilse to salmon in any particular river. When 
we come to deal with rivers, however, it has to be 
remembered that we introduce not infrequently the 
complications due to the action of man in, it may be, 
overfishing or in polluting the fresh water, and that 
changes may be going on which prevent our regard- 
ing the results found as normal. In the Tweed, for 
instance, the early reports show, according to Willis 
Bund, that from 1808 to 1853 there were never less 
than three grilse to one salmon, and that from 1853 
to 1876 there were two grilse to one salmon. In later 
years the grilse have continued to diminish. In the 
Severn they have apparently become rather con- 
spicuous by their absence. 
Hoek at the mouth of the Rhine found that 
grilse formed only 24:1 per cent. of the fish ascend- 
ing that river. Observations such as these are 
necessarily made only during the fishing season, 
while, as I have already said, winter netting in 
“The Habits of the Salmon,” p. 88. 
