How to obtain tt. 181 
creeping things found at the bottom of our streams, almost without 
exception, prey extensively upon trout ova. Every fish culturist 
has found these creatures at some time or other coming down into 
his hatching boxes. The filters will not keep them out. They are 
sO minute, in their early stages, that they are practically invisible, 
and they get in unobserved, and then grow so fast that soon they 
cannot get out again. In a well managed hatchery, however, the 
trouble arising from this cause is trifling. But in a stream, 
matters are very different. There are creatures innumerable, all 
instinctively attracted to the place where the eggs are deposited,— 
caddis worms, creepers, shrimps, beetles, frogs, mice, rats, ducks 
and other fowl, eels, trout, grayling, salmon, sea-trout, and nearly 
every other fish found in the streams. Nearly everything ranks as 
an enemy to trout ova. Therefore it is apparent, that by pro- 
tecting the eggs, we are doing a great deal. But we are doing 
more, for the artificial beds shelter the “alevins” for awhile, and 
after they drop down the little artificial stream they are still 
shielded from the bulk of the dangers enumerated, especially 
from the depredations of trout and other fishes. 
The streamlet used as a hatching bed should be so con- 
structed that no outsider of the trout family can by any possibility 
get into it. Eggs, before hatching, have no power of protecting 
themselves, or of getting out of the way of danger. As soon as 
the embryo is out, it at once possesses some power of self-protec- 
tion. It has a pair of well-developed eyes, and knows how to use 
them, and immediately that wonderful power called instinct causes 
it to seek a hiding place. So strong is this desire to hide, that if 
the little creatures cannot find any other place they will hide 
under each other, and in doing this they gather together in dense 
masses, reminding one of a swarm of bees. 
Californian baskets, which are simply wire cages in which 
eggs are piled one above another, do not suit the eggs of our 
British Sa/monide. It is true that by using them a large number 
of eggs can be hatched in a small space, but the result is undoubt- 
edly a partial suffocation of the embryos, and a general weakening 
of the young fish. They may do well in America, but what will 
suit the fish of one country often may not agree with the fish of 
another. A lower prevailing temperature is, no doubt, to some 
