Monstrosities 245 
effect on the growth of the fish all through its life. In hatcheries 
overcrowding would seem to be the cause of these malformations. 
Deformed trout, however, are also found in rivers and lochs where 
overcrowding is impossible and food plentiful, so that deformities may 
be due to other causes, such as injury to the eggs or fry (see Fig. 216). 
Many deformed trout are found similar to this (see Fig. 217). Such 
deformity could scarcely be caused by injury to the eggs or fry. It 
points more to want of development, and very likely the parent would 

FIG, 225.—2-lb. Deformed Trout, caught in Loch Dupplin. December 1907. 
have a similar short head. The twisted backs may be caused by a 
weak spine. There are fewer deformities among salmon and _ sea- 
trout than among trout. Perhaps they may not be able to survive 
in the sea, and die off. Hundreds of salmon are found with so great 
gashes in them, made by seals and other enemies, that it 1s a wonder 
they manage to live. These injuries often heal up, but one can always 
note their effect on the fish, as they retard growth, causing them 
to become thin and of inferior condition. Many monstrosities are seen 
in the salmon hatcheries. Some of them have two heads, while some- 
times two are joined together, as we occasionally see in the case of 
beasts and birds. Asa rule these fish die when about six weeks old. 
When deformed fish are discovered they should be destroyed. 
