62 TROUT AND GRAYLING. 
vessels, but only one umbilical sac, and one tail; or else they have 
two heads to one body. It is needless to say that these 
monstrosities are short-lived, but they sometimes live six or eight 
weeks, until the yolk sac is absorbed. When the eye spots have 
appeared the eggs are called ‘‘ eyed ova,” and may be handled 
without fear of hurting them, and they may be packed in damp 
moss and sent to different parts of the country to be placed in 
streams and hatched out. As soon as the yolk sac is absorbed, 
at which stage the young fish are called “fry,” they begin to 
require feeding. Their natural food consists of flies, worms, 
freshwater snails, and shrimps, minnows, and other small fish, but 
at Milton they are fed upon raw horse flesh, which is chopped up 
very fine by a machine. ‘The fry are placed in ponds by them- 
selves, and in order to give them their food in pieces small enough 
for their little mouths, it is washed through a fine wire sieve, so 
that no fibre of the meat gets into the water. At the end of the 
year it is generally found that out of about 200,000 fry put into the 
ponds, there are only about 70,000 that have grown up and 
become what are called yearlings, and these are from 4 to 6 
inches long, and may be looked on as really healthy fish. Each 
pond has at one end of it a covering of boards as a shelter for the 
fish. 
In another pond at Milton are some splendid grayling which 
were brought some years ago from Lincolnshire. These fish 
spawn inthesummer, and their eggsare very much smaller than trout 
eggs, and hatch in from twelve to twenty-five days. The young 
grayling require almost more care than trout, as the least impurity 
in the water is fatal, and what is good enough for a trout may not 
do for the grayling. 
The trout and the grayling belong the family known as the 
Salmonide, which includes the salmon, all the different sorts of 
trout. the char, the grayling, and one or two others. 
In examining a trout or a grayling, a small fleshy appendage 
will be found close behind the dorsal fin. This is called the 
adipose fin, and is common to all the Sa/monide ; it does not seem 
to be of much use to the fish, but is handy for attaching a small 
