Sea Prout 155 
spots there are on their sides the more parasites are there in their gills, 
and sometimes the gills are nearly eaten away. See illustration of a 
gill (Fig. 148), and also illustration of the difference between a salmon 
(Fig. 150) and a salmon bull-trout (Fig. 149). These fish are inferior 
to the salmon, and usually bring twopence to threepence per pound less 
in the market. Their flesh is often whiter and not so well flavoured. 
Having had several bull-trout from the Tweed, I could discern a great 
difference between them and the bull-trout of the Tay. Several years 
ago I drew the attention of Sir Herbert Maxwell to them, and he was 
astonished to hear that we had bull-trout up to golbs. and over. Having 
captured one 42 lbs. shortly afterwards, I sent him a photograph of it, 
and he declared it to be a bull-trout. I also brought them under the 
notice of Dr. Kingston Barton for examination, and he found them to 
be seventeen per cent richer in fat than other salmon. 
When he called one day at our fish-house, | drew his attention to 
the spots on the fish, and he thought the richness of the feeding might 
cause these as well as the parasites in the gills. Since then our 
marking of fish on the Tay has clearly proved that the so-called bull- 
trout of the Tay and many other rivers are true salmon. These bull- 
trout should not, of course, be confused with the bull-trout of the 
sea-trout. The former have the same number of scales from the 
dead fin to the lateral line as the salmon. All the grilse kelts, small 
spring fish kelts, and in fact all the kelts which we marked, were 
so-called bull-trout when they returned again. I have watched 
them carefully in our fish-house, and in July 1907 there were nineteen 
per cent of them. 
It is remarkable that almost all the bull-trout are females, and 
this is, no doubt, accounted for by the fact that there is greater 
mortality among the males during the spawning season, thus leaving 
few but females to mark. From the study of these I am now con- 
vinced that all fish—salmon, grilse and sea-trout—that have spawned 
are inferior to fish that have not spawned. It was indeed an “ eye- 
opener” to me to find one of our wired smolts of 1905 return on oth 
August 1907 for the first time weighing 27 lIbs., for hitherto we 
