Of course, images in focus were less blurred than those
out of focus in both upper and lower of micrographs in
Fig. 14. However, the appearance of paired images differed
between the upper and lower micrographs. Of the four
images the edge was the clearest in a focused image of
the object placed at a distance of 100 mm, while the most
widely blurred in the defocused image of the object was
the one placed at a distance of 10 mm, as shown in the
lower micrographs. On the other hand, the edge is less clear
even in the focused image of the object at a distance of
10 mm as shown in the upper micrograph. Such differences
are shown more quantitatively as a density distribution. In
the lower micrograph the density of the edge gradually
changed for a width of 2 lm for the focused image of the
object at a distance of 100 mm, whereas the width was
7 lm in the out-of-focus image of the object at a distance
of 10 mm. In the upper micrograph the blurred edge was
3 lm and 5 lm wide for images in and out of focus,
respectively.Friederichs (1931), however, because of the different size
of eyes used between the two works. Even so, if we compare
stemmata of similar sizes in the two studies, the optical
and morphological data are very close between both.