39 6 Wisconsin state agricultural society. 
more. Our advice is, to use only enough water to fairly cover 
the eggs, and until further experiments are made not to use less. 
Natural impregnation .— Some years since it was thought that a 
universal panacea for all the ills of trout-breeders, had been found 
in the discovery of a means of natural impregnation. The first 
invention was made by Mr. Stephen H. Ainsworth, a name well 
known to and honored by all fish-breeders. His invention was 
followed by others, using the same principle, but economizing 
time and labor to such an extent that if the naturally-impregnat¬ 
ed eggs had really been any better than those artificially impreg¬ 
nated, the system would have been perfect. Even now there is 
great diversity of opinion among trout-breeders, some persons not 
being willing to use any but naturally-impregnated eggs, and 
others making no use of them whatever. We ourselves perfer 
the eggs artificially impregnated, for several reasons. One reason 
is that many more eggs can be impregnated in this way then by 
the natural process. If any one will take the trouble to dig up 
the eggs laid by wild trout in a natural stream he will find that 
but a very small proportion bear marks of impregnation, the per¬ 
centage varying from 3 to 10 per cent. The races put down on 
the Ainsworth plan do much better than this, the proportion of 
eggs impregnated being perhaps 75 or 80 per cent Then, also, 
the eggs taken from the Ainsworth screens are mixed with sedi¬ 
ment and fibers of woody matter, saturated with water, which are 
a source of great annoyance; and besides this, in order to get all 
the eggs from a pond full of trout on the natural plan, the area 
of screens should be three or four times as great as the usual area 
of race employed for stripping purposes. Now, the chief claim 
of those who urge the use of naturally-impregnated eggs is, that 
they grow into better, stronger, more hardy, and more healthy 
fish then the other. If this was the case the difference of percen¬ 
tage in impregnation, etc., would not be worthy of consideration. 
But after some years of experiment it looks to us as if the advan¬ 
tage, if any, was rather on the side of the artificially-taken eggs. 
Why this should be so is a mystery, as, theoretically, naturally- 
impregnated eggs should be perfect. We recommend methods of 
natural impregnation only to beginners in the art, or for use in 
places where it is not convenient to take the fish at proper seasons. 
