THE REDUCTION OF FUSIFORM CAMBIAL CELLS IN CHAMAECYPARIS AND THUJA

Abstract

The loss of fusiform initials from the cambium, which is of frequent occurrence in all parts of the tree, takes place in different ways. Some cambial cells seem gradually to fail and are shortly lost from the cambium by maturation into more or less imperfect xylem or phloem elements. The majority are transversely subdivided by one or a succession of anticlinal divisions which begin near the center of the fusiform initial and usually extend to the daughter cells. The resulting segments shorten through the following periclinal divisions, some disappearing during the process of shortening and others undergoing transformation to ray initials. Nearly all new rays in the secondary body originate in this manner.