Driesch
studied the process by which organisms are able to replace or repair damaged
structures. Plants have an amazing range of regenerative capabilities, and the
same happens with animals. For example, if a flatworm is cut into pieces, each
piece regenerates a complete worm. Many vertebrates have extraordinary
capabilities of regeneration. If the lens of the eye of a newt is surgically
removed, a new lens is regenerated from the edge of the iris, whereas in the
normal development of the embryo the lens is formed in a very different way,
starting from the skin.
The Vital Needs Theory - page 65