ought to give, as regards the influence of the corpuscles
of the father and of the mother upon the result of the
industrial culture, or of the culture for eggs, information
which could not fail to be very important, whatever
might be the true significance of the corpuscle itself.
In fact, advancing with this light, Pasteur perceived
immediately a certain number of facts of the greatest
importance.

The first fact was that on a large scale in the industrial
culture the batches of eggs behaved worse and worse,
that is gave less and less cocoons, in proportion as the
parents were more and more occupied by corpuscles.
This sufficed to establish between the existence or the
number of the corpuscles and the presence of the disease,
the bond of union which was the first need of the new
method.

The second fact was that eggs laid by corpuscular
moths were not, per se, destined to miscarry, and might
develop good cocoons giving acceptable yields. Such
was, for example, the case of the eggs received from
Japan, which, although corpuscular, were nevertheless
much sought after by silk-growers. This robust race
seemed better to resist the prevalent disease. Such was
also the case for several cultures of French races. But
none of these cultures, even those which had yielded the
greatest number of cocoons, could give good eggs,
because all the moths were strongly corpuscular. This
explained why one sometimes miscarried in selecting
eggs derived from a successful culture. The success
of this culture proved nothing as to the egg. In addition,
control by means of the microscope was necessary.
And so one came back to the method of egg-selection,
authoritatively recommended by Pasteur, this being
brought forward once more, singularly strengthened
by its first trial.

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