The cells of the procambium are elongated and become even more so in the course of their development. The volume of their vacuoles increases considerably, giving them a lighter and more transparent appearance than their neighbouring cells. This is decisive for their differentiation into cells of the xylem or phloem. The depicted determinations were made to characterize the growth within the different levels. In plants with secondary growth keep some of the meristematic cells their meristematic state and become thus cells of the cambium.
Induction is achieved by fully differentiated tissues.
The necessary information is conducted to the bud via already differentiated cells of the procambium. The first model could be confirmed experimentally, since formation and further development of the procambium are undisturbed in isolated bud meristems. The determination of cells takes place before any morphological change can be seen. Determination is the process by which cells are tied down to a certain differentiation by adjustments in gene expression, metabolism and regulation of cell activities, while during differentiation the determined process is carried out. The cambium is the prototype of a lateral meristem.