9 
papers that a mackerel of six or even eight pounds weight 
has been caught, but in every instance in which I have 
been able to make inquiries the fish has turned out to 
belong to an allied species—the short finned tunny—which 
sometimes herds with the mackerel. 
There is one fact about the personal history of this fish, 
which I will mention although I know I do it at the risk of 
having my veracity suspected; but I narrate only what I 
have seen over and over again, have repeatedly shown to 
my friends, and am prepared to show in the cases of two 
fish out of three, to any one of you who will call on me at 
Penzance and go out and catch mackerel with me. The 
mackerel, like the turbot, requires, and has, enormous 
muscular power at the tail to give the tail-fin its full 
advantages. In the turbot the fishermen recognise this 
fact and say that the turbot has a “second heart,” and, as 
soon as they can, after they have caught one, they, at least 
in our parts, “ bleed it,” that is, make an incision on the 
line of the lateral line on the white near the tail, which cuts 
into this “ second heart,” and from which the fish bleeds 
freely. They have an impression that it whitens the white. 
Now, for my mackerel. The strongest and most muscular 
fish are those which wander about by themselves, and take 
surface bait, and it is on these only that my experiment 
has been tried. Take one of these immediately it comes 
into your boat, and, at once, without injuring it more than 
is necessary, prepare it for the gridiron just as your cook 
would, and lay it on the deck of the boat. In a short time 
a muscular action will develop itself in the tail, and 
the disembowelled fish will turn a clear summersault, some¬ 
times two, and occasionally three, and will then become 
quiet after a convulsion in which every fin vibrates. Like 
many other discoveries this one was made by accident; but I 
