. Beihefte zum botanischen Centralblatt. Plants. Fig. 5. Seedling of Vicia faba. Method of bending when opposed by bar of cork. The foregoing result would seem to demonstrate the geo- tropic sensitiveness of the part of the root behind the apical 3 mm. There can be no doubt that the curves are not plastic. Some, however, may hesitate to pronounce against the possible participation of hyclrotropism and thigmotropism in producing the curves when the corkbars were employed. Such doubters are re- ferred to my papers on The Rheotropism of Eoots!) and Thigmotro- pism of Terrestrial Roots2), in which
. Beihefte zum botanischen Centralblatt. Plants. Fig. 5. Seedling of Vicia faba. Method of bending when opposed by bar of cork. The foregoing result would seem to demonstrate the geo- tropic sensitiveness of the part of the root behind the apical 3 mm. There can be no doubt that the curves are not plastic. Some, however, may hesitate to pronounce against the possible participation of hyclrotropism and thigmotropism in producing the curves when the corkbars were employed. Such doubters are re- ferred to my papers on The Rheotropism of Eoots!) and Thigmotro- pism of Terrestrial Roots2), in which it is shown that, even in un-. 1° °l Fig. 6. Seedling of Vicia faba. Tip kept from bending by 2 bars of cork. injured roots of Vicia faba and Cucurbita pepo, such curves as are recorded in this paper are never produced by cork in con- tact with one side either of the tip or the part behind the tip of the root. To make the matter doubly sure, two other experiments were set up quite similar to the last, except that strips of cork were brought into contact with both sides of the tip of the root, as shown in Fig. 6: Six seedlings of Vicia faba had each 3 min of the tip removed, and the seedlings were tuen prepared in the damp-cham- ber with their tips between cork bars as indicated. revolved for 7 hours at 8 g in temperature ° and then observed. Only *) Bot. Gazette. XXXIII. 1902. 177. 2) Beih. z. Bot. Oentralbl. XYH. 1904. 61,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Leipzig : Verlag von G. Thiem
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