MISCELLANEOUS: EXPERIMENTAL TERATOSIS 599 



first of December it did not seem as if the plants would ever 

 produce smooth leaves, but during the second four months, in 

 which the plants remained undisturbed and were watered spar- 

 ingly but regularly and sufficiently, they proliferated either not 

 at all or scarcely at all, producing several hundred smooth leaves 

 and internodes, so that on March 15 each one of the 29 plants 

 closely resembled the plant shown on Fig. 425. 



When finally examined on March 15 nearly all of the lower 

 very proliferous leaves 3 had fallen (see Table III) but there 

 were still a large number of proliferations visible on the lower 

 internodes, that is adventitious growths on the lower 5 to 9 

 inches of the stem, corresponding to the stimuli of July 12-15, 

 August 6, September , and November 12, but all of the upper 

 15 or 20 inches of the plant was so nearly free from adventive 

 shoots that one would say entirely free until he examined 

 closely, when a few shoots were found here and there on the 

 leaves iand internodes, but in no case dozens or hundreds, as 

 during the first period. Great numbers of the leaves were 

 particularly fine and smooth. In other words, undisturbed, 

 the plants ceased to proliferate, except around the stipule 

 scars which are places more subject, it would seem, to loss of 

 water than other parts and which always proliferate except 

 on the youngest nodes, upper 4 to 6 inches of the stem (Fig. 

 445 St) where the stipules are still living. The above state- 

 ments hardly express the full difference, because at the close 

 of the experiment (March 15) there were more than 800 smooth 

 leaves, whereas on the first of December there was not a single 

 one. 



22. It now remains to consider the nature of this shock, 

 since merely to say that wounding causes it, or that it is the 

 plant's response to a wound, does not satisfy, and especially 

 not, because the place of response, as we have seen, may be very 

 far away from the place of wounding, i.e., as far as from the 

 roots to the top of the plant. I have only a hypothesis to 

 offer, but it is confirmed by the experiments, fits in very well 



B. No. 9, second series, main axis. A small portion of the proliferous petiole 

 of Leaf M (Fig. 438) enlarged. Nearly every trichome has developed a shoot. 

 X 4. 



