In this Atlas I want to share with my fellow clinicians the fascina-
tion I experienced while discovering the marvels of embryonic
development. Why haven't these marvels excited me before? I believe that
the use of schemata and drawings or photographs of animal embryos,
commonly used in textbooks of embryology, simply did not appeal to me as
a clinician. Only actual photo- graphs of human embryos can establish
the bond necessary for interaction. Just imagine the excitement when you
find out how many struc- tures you can recognize in a 5-week-old embryo,
barely measuring 1 cm in length. But our fascination does not stop here.
The pro- gression of changes taking place during the next 3 weeks is so
rapid that at the time when the embryo measures 3 cm, all structures
familiar to us are not only easily recognizable, but also already in
their anatomical position. How can we hide our amazement when we realize
that such a state of perfection is present in an embryo a bit longer
than the distal phalanx of our little finger? At 8 weeks the embryonic
period ends and the fetal one starts. Although the shape and the
relative size of bones, joints, muscles, nerves, and vessels will
undergo changes, the basic elements are all in place. This implies that
major malformations must develop during the embryonic period.