28 SALT-WATER FISHES 



at approximately the same time — in one shoal. They are not, 

 of course, the offspring of the same parents, but have simply 

 joined forces from a preference for company. Not all fishes 

 go thus in shoals. The angler may sometimes catch a single 

 dory among a hundred fishes of two or three other species. 

 The sun-fish is generally described as solitary, and, in the 

 writer's opinion, the same may be said of most of the larger 

 sharks in our seas, though the smaller "hounds" undoubtedly 

 hunt, like their namesakes on land, in packs. Even mackerel 

 and pilchards only gather near the surface in shoals during some 

 parts of the year, and the pilchards even disperse during the 

 summer nights to feed separately, with their heads pointing 

 away from the land ; hence, as will be explained in the next 

 chapter, the rationale of the drift-net. The break-up of the 

 mackerel shoals, too, and the subsequent capture of the fish on 

 leaded ground-lines, is an annual experience with the fisher- 

 men, and corresponds approximately with the break-up of the 

 summer weather. 



It can hardly be contended, unless instinct is more at fault 

 than usual, that the habit of shoaling in fishes is associated 

 with any notion of protection, for a moment's reflection will 

 show that the mackerel or pilchards would be infinitely safer 

 singly than they can possibly be in shoals, far less likely to 

 attract the attention of their enemies, far less vulnerable by the 

 bills of sea-fowl, the jaws of porpoises, or the nets of man. It 

 has certainly been said, and by no less an authority than the late 

 Matthias Dunn, that a dense shoal of mackerel has been all 

 but known to suffocate a grampus that had inadvertently 

 plunged into the midst of the crowded fish, but such an 

 episode must be very rare. The writer has repeatedly seen 

 both grampuses and thresher sharks busy among very large 

 shoals, and never with any result beyond, so far as could 

 be judged, the destruction of an immense quantity of the fish. 



The distribution, or geography, of our sea fish is an 

 immense subject, and one that might well occupy a chapter, 



