March, 1922] TELLEFSEN — 
RELATION OF AGE TO SIZE 
Table 20. Measurements in Cross Section of Xylem Root Cells of Cuttings of Trees of 
Salix nigra, Group B 
Ave. Measure, 
Number of Tree Diameter of Tree 5 Cells 
(Inches) (Microns) 
58 4 9-96 X 8.54 
62 4 8.96 X 11.95 
68 4 9.29 X 10.62 
167 4^ 10.95 X II. 18 
330 5 9-29 X 9-29 
405 4 11.62 X 12.94 
601 6 7.30 X 13.28 
609 4 9.62 X 10.60 
612 5 11.28 X 10.95 
621 5 14.94x14.27 
623 6 8.96 X 9.46 
627 6 1 1.28 X 6.97 
633 4 12.78 X 13.61 
635 5 940 X 12.17 
639 4 15.93x18.92 
641 6 10.79 X 10.79 
642 5 10.29 X 9.62 
700 5 11.95 X 11.95 
706 6 10.61 X 13.28 
Average 10.80 x 1 1 .61 
Table 21. Measurements in Cross Section of Xylem Root Cells of Cuttings of Trees of 
Salix nigra, Group C 
Ave. Measure, 
Number of Tree Diameter of Tree s Cells 
(Inches) (Microns) 
35 10+ 13.78 X 13.61 
44 10 12.28 X 17.59 
46 18 8.63x11.95 
48 10 11,62 X 11.97 
326 13 9.96 X 8.46 
327 13 10.61 X 17.26 
328 13 8.13 X 9.13 
404 •• 15 11.29 X 10.95 
602 20 9.15 X 12.95 
604 10 11.78 X 11.78 
605 9 9.62 X 10.60 
611 8 10.45 X 12.61 
620 8 9-97 X 9.96 
624 10+ 11.29 X 12.95 
625 lo-j- 11.29 X 9-30 
628 8 10.96x10.29 
629 8 10.62 X 10.96 
630 10 11.62 X 13.28 
631 8-10 ' 10.96 X 12.61 
634 10 13.94x14.94 
643 10 11.29 X 12.12 
702 10+ 13.61 X 10.63 
703 10+ 1 1.62x10.51 
704 10+ 12.28 X 9.95 
705 10+ 1 1.62x13.92 
708 8 9.63 X 9.30 
Average 1 1 .07 x 1 1 .90 
