14 THE SALMON FISHERIES. 
enters. When thus fertilized and left in water of a suitable 
temperature, from 40 to 50 degrees, the embryo in the egg 
gradually develops, the first sign of life being two little 
black dots, representing the eyes of the nascent fish ( Fg. 2). 
These are followed by a “thin red line” denoting the verte- 
bre : and the development of the fry continues till the shell 
of the egg bursts, and the newly-hatched salmon makes its 
appearance on the world of waters in the shape represented 
in the accompanying drawing—like a tiny strip of gelatine, 
with a little round head, and a large bead of yellowish 
red colour attached underneath ( Fg. 3). 
For six weeks or so it is a helpless infant, breathing 
the air in the water after the manner of an adult fish, but 
eating nothing, subsisting only on the oily contents of the 
umbilical sac or vesicle attached to the abdomen. As this 
is gradually absorbed into the system, the young fry 
shows greater activity, swimming about in a lively manner 
a few inches at a time. 
When the umbilical sac is quite absorbed, the fry, which 
looks like a fish for the first time, begins to search for 
food ; that is to say, if it lives long enough to reach this 
stage of its existence, for the movements of the little 
animated bags attract crowds of fresh enemies, by which 
the motionless eggs had been overlooked. Fish of many 
kinds find in them a congenial food, both abundant and 
easy of capture. Kingfishers and other birds join in 
the feast, and still further reduce the possibility of the 
thousands and tens of thousands of eggs deposited by 
each female salmon doing much to keep up the future 
supply. 
Those that are fortunate enough to survive the onslaughts 
of a long array of natural enemies increase pretty rapidly 
in size. The accompanying cut ( /zg. 4) and the lines a, 4, 
