confirm Wolff's theory of epigenesis.

This resuscitation of embryology and development of the
epigenesis-theory was chiefly connected with the university of
Wurtzburg. One of the professors there at that time was Dollinger, an
eminent biologist, and father of the famous Catholic historian who
later distinguished himself by his opposition to the new dogma of
papal infallibility. Dollinger was both a profound thinker and an
accurate observer. He took the keenest interest in embryology, and
worked at it a good deal. However, he is not himself responsible for
any important result in this field. In 1816 a young medical doctor,
whom we may at once designate as Wolff's chief successor, Karl Ernst
von Baer, came to Wurtzburg. Baer's conversations with Dollinger on
embryology led to a fresh series of most extensive investigations.
Dollinger had expressed a wish that some young scientist should begin
again under his guidance an independent inquiry into the development
of the chick during the hatching of the egg. As neither he nor Baer
had money enough to pay for an incubator and the proper control of the
experiments, and for a competent artist to illustrate the various
stages observed, the lead of the enterprise was given to Christian
Pander, a wealthy friend of Baer's who had been induced by Baer to
come to Wurtzburg. An able engraver, Dalton, was engaged to do the
copper-plates. In a short time the embryology of the chick, in which
Baer was taking the greatest indirect interest, was so far advanced
that Pander was able to sketch the main features of it on the ground
of Wolff's theory in the dissertation he published in 1817. He clearly
enunciated the theory of germinal layers which Wolff had anticipated,
and established the truth of Wolff's idea of a development of the
complicated systems of organs out of simple leaf-shaped primitive
structures. According to Pander, the leaf-shaped object in the hen's