PROPAGATION OF SALMON ON THE PACIFIC COAST. 
223 
the head of the salmon in one hand and to press the spawn ont with the other, another 
person being employed meantime in holding’ the tail of the fish to keep it still. This 
is the method uniformly adopted at Baird station. On the Columbia, however, where 
the salmon are larger and more nnmanag’eable, the “straight-jacket,” as it is called, 
is nsed. This is a sort of trough, made the average length of the salmon and hollowed 
out to tit in general the sliape of the fish. Across the lower end of tlie trough is a 
permanent cleat, and at the upper end a strap with a buckle. The fish, when manip- 
ulated, is slid into the trough, the tail going down below the cleat, whei’e it is securely 
held, and the head being immediately buckled in at the upper end with the strap. 
The fish is now securely held, and is unable either to get away or do any damage by 
its flonuderiugs, and the eggs can be i)ressed out at leisure. The straight-jacket is 
almost indispensable with very large salmon, and a great convenience when the 
operators are short-handed. This is the method that has been generally employed at 
Clackamas station. 
There is one more method of holding the fish that ought to be mentioned, which 
can be adopted with medium-sized salmon, and which might be called the one-man 
inethod. By this method, the operator holds the head of the salmon tightly between 
his knees, and, keeping the tail of the fish still with one hand, he presses out the ova 
witli the other. This is a good way where there are only one or two men to attend to 
the spawning. 
IMPREGNATING THE EGGS. 
As in holding the siiawuiug salmon, so in impregnating the eggs, all methods 
employed by enlightened fish-culturists are, in their general features, the same, the 
main points to be secured in all cases being identical, viz, to keep the eggs perfectly 
dry till the milt is applied, and to use the utmost dispatch in causing the spermatozoa 
of the milt to mingle Avith the eggs after the eggs are expressed from the fish. 
The eggs, Avhen they first leave the fish, have such an active absorbing power 
that they will very rapidly absorb any liquid that they come in contact with, and if 
taken in water will absorb the water so quickly that most of them become filled with 
water before tlie spermatozoa reach them, or rather before tliey reach the micropyle. 
But while it is a singular fact that the sj)ermatozoa of the milt will die in water in two 
to three minutes, a little water is necessary to stimulate them into efficient activity. 
Consequently, Avhile the eggs should be taken iierfectly dry, a little Avater should be 
added to the milt, but the instant this is done the slightly diluted milt should 
be poured on the eggs. If the eggs are taken in one pan and the milt in another, 
simultaneously, and mixed together the instant they are ready, a very high rate of 
impregnation may be secured. 
In actual practice at this station, one pan only has been generally used, and a 
very good imin’egnation has been secured in that way, bnt with only one pan the 
maniiAulations must be made quickly, and the rule must be obseiwed to take the 
eggs dry and to introduce the diluted milt almost simultaneously with the taking of 
the eggs. 
To obtain a high rate of impregnation, these points must be secured: 
(1) The eggs must be taken dry. 
(2) The milt must be taken simultaneously with the eggs. 
(3) The milt must be diluted with a little water. 
(4) The eggs and milt mixed together instantly after the diluting of the milt. 
