1) The writer observed the relation between cell division and cell elongation in the decapitated roots. And in order to simplify the study the cell division was studied chiefly in portions within 4 mm from the root apex and the elongation in the portions basipetal from that point. 2) Measuring the roots cultivated in saw dust, it was found that the elongation of the portions besipetal from the 4 mm point of the roots decapitated at 3 mm or 4 mm from the root apex is less than the intact root; and that the 1 mm decapitated roots, 24 hours after decapitation, elongate rather longer than the intact roots (control), yet the 1 mm decapitated roots, 4 hours or 7 hours after the cutting, elongate in a still lesser degree, compared with the intact roots. Next, measuring the portion within 4 mm from the root apex, it was seen that the elongation of all the decapitated roots was always less than the intact root. In the cases of experiments of materials cultured in water, it often happened that decapitated roots elongate longer than the intact roots, especially concerning the portion within 4 mm from the root apex, the elongation of the 1 mm decapitated root was always longer than that of the intact root. However, this is probably to be attributed to the disturbance of the normal elongation, by superfluous stretching, caused by the excess of water. 3) Putting together the results of measuring the water content of the portion of root, on which the elongation was observed, and other several experiments, it is likely to be assumed that by cutting or by other analogous operations the water content or turgor of the portion is mindered, and this must be one of causes inhibiting the elongation. 4) The cell lengths measured in the positions basipetal from the 4 mm point, run parallel to the rate of elongation of corresponding portions. 5) Diminution of the frequency of cell division is seen at the portion near the cut surface. 6) What is the cause of the diminution of cell elongation and cell division, in the decapitated roots, is beside the question in our case, yet the diminuent of the frequency of cell division as well as retardation of elongation of cells go together side by side. And this result is parallel with the cases of inhibition of growth of the root treated by gypum or sugar solution. 7) In considering the final results only of such experiments one may come to an erroneous conclusion, because there are several related indirect phenomena such as the formation of calli or adventive roots etc. , besides the direct effects of cutting upon the division and elongation of cells, which is the only question which should be analysed here.
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