Anticlinal Divisions and the Organization of Conifer Cambium

The multiplication of radial files of axial elements, which accompanies girth increase, is usually duplicated in xylem and phloem, but sometimes the expansion is temporary and occurs only in the xylem. Because such additions are traceable to anticlinal divisions in the cambium, the deduction follows that permanent changes in cell pattern are due to multiplicative divisions in cambial cells having the initial function, and changes in the xylem only, to divisions in cells on the xylemward side of the initials. A distinction between initial cells and derived tissue mother cells, as proposed by Sanio (1873), is thus confirmed. However, indications of occasional lapses in the initial function cast doubt upon the suitability of restricting the term "cambium" to initials only.