of his arteries may not disturb the steadiness
of his gaze, and the condition of his nervous
system be so calm that his whole figure will re-
main for hours in rigid obedience to his fixed
and concentrated gaze.

After these remarks I trust I shall not be mis-
understood by those who have been working in
the field of microscopic investigation, and for
whose persevering devotion no one can feel a
deeper reverence than I do, if I add that there
is as yet hardly a beginning in the study of the
egg during its growth, and anterior to the for-
mation of the germ. Since Embryology became
a science, the great aim of students in that de-
partment has been to demonstrate the uniform
structure of the egg in all animals, and investi-
gators have limited their observations to that
stage of the ovarian egg during which it ap-
pears in all animals as a perfect cell. But a
new field now opens before us, requiring a care-
ful survey of every stage of growth of the egg,
from its first formation to the period when a
well-defined germ is developed. The growth of
the egg during this period requires to be studied
as minutely through all its changes, and in the
various combinations of its constitutive elements,
as the germ itself has been in its later trans-
formations. Here again, in this later phase,
another field presents itself equally new and

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