During the past decade remarkable strides have been made in the field of growth substances in general and in their practical application in various aspects of vegetative propagation. Anatomical and morphological studies appear not to have kept pace with more practical considerations. In particular, innumerable useful tools in the form of “hormones”, growth substances and new techniques have been put at the disposal of the plant propagator. But many gaps remain in our scientific knowledge as well as our art, and we still have very little basic knowledge concerning protoplasm and how it behaves in the various aspects of plant regeneration.