GLIDING GROWTH AND THE BARS OF SANIO 
one side into a direction more or less parallel to that of the rays, as 
may be seen in figure 2. Much variation was evident in the length 
of that portion of cells that was diverted from the direction of the 
other wood cells toward that of the rays ; in one instance the diverted 
portion was found to measure 15.7 fx in length (figure 3). In several 
Fig. 2. Longitudinal, Radial Section Fig. 3. Longitudinal Section of Apple 
of Apple Wood. a and h, large vessels. Wood, showing one cell that has under- 
r, medullary ray. gone considerable independent elonga- 
tion. V, large vessels, r, medullary ray. 
instances pits were found on the convex side of such bent wood cells 
in positions where the cell was not in contact with any other. Such 
cases were found in the bent groups outlined in figures 2 and 5. 
The diverted tips seem to have grown in various directions. In 
figures 3 and 5 the growth was along the ray toward the bark, which 
Fig. 4. Section of Apple Wood, q)^ow- Fig. 5. Section of Apple Wood, show- 
ing various degrees of elongation of xylem ing a group of xylem cells diverted at 
cells. V, large vessel, r. medullary ray. end by encountering a medullary ray, r. 
