182 BACKBONED ANIMALS. 
from Greenland to Cape Hatteras. During the winter they 
run in deep water, coming in-shore in May and June to 
spawn, each female depositing from 500,000 to 600,000 
eggs, that rise to the surface and float about. After spawn- 
ing the fishes keep on up the coast until they meet cold 
water, and at this time are taken all along the shore in vast 
numbers, entire fleets of vessels being engaged in the trade. 
Allied is the Spanish mackerel, the bonito, and the horse- 
mackerel, that attains a length of twelve feet and a weight 
of 1,200 pounds. 
NoTe.—The mackerel is a light-giver (phosphorescent), and so 
bright is the light of great schools that the fishermen see it at night 
from aloft, and, by surrounding it with a seine, capture the school. 
The large allied Jacks (Cavanx), of the extreme outer Florida reef, in 
feeding, rush in thousands upon the beach of the keys, driving schools 
of small fish before them, leaping upon the sand, and striking the 
water, creating a sound that can be heard a mile. The occurrence’ is 
called a ‘‘Jack-beat.” The fishes are utterly oblivious to their sur- 
roundings, and fishermen stand knee-deep in the almost solid mass, 
and spear or hurl them ashore with their hands. Pelicans, gulls, man- 
of-war birds, and human fishermen, all know the sound, and gather 
from far and near. 
Sword-Fishes (Xiphiide).— The sword-fishes (Fig. 
224) have the upper jaw developed into a long, sword-like 
projection ; they attain a length of from eleven to twenty- 
five feet, and the 
different genera 
are found in va- 
rious seas; they 
feed upon mack- 
erel and other 
Fic. 224.—Sword-fish (Xzphias). fishes, dashing in- 
to the schools, 
cutting their victims down, and picking the dismembered 
parts up at leisure. The sail-fish (Histophorus), of vari- 
ous seas, has an enormous dorsal fin, that appears like a 
sail when the fish is at the surface. The sword-fishes do 
