STUDIES IN PLANT REGENERATION 213 
Experiment 24. — Parts with eyes removed in the manner 
described were cut into halves and quarters like Rechinger's and 
planted with the cut end down. These formed shoots, though not, ^ 
as in Rechinger's results, at the large cuts, but in the region of the 
original bud. In no case was a shoot found on such a cut. 
Experiment 25. — Pared potatoes as wholes and in parts were 
next tried, but although some of these resisted decay for four 
months, no shoot ever appeared. 
Experiment 26. — The buds formed on the potatoes of experi- 
ments 23 and 24 were repeatedly removed, but new ones con- 
tinued to form, sometimes in the same place, sometimes at a dif- 
ferent node. If the parts were left undisturbed, shoots finally 
appeared at many of the nodes as іп the uninjured tubers. Мо 
polarity could be observed in the appearance of the buds. They 
were formed with apparent indifference at any of the cut regions, 
without reference to apex, base, dorsal or ventral surface. Хо 
roots were formed in the specimens under observation. Modified 
stems of other types — thorns, tendrils, and rhizomes from which 
the buds were removed did not regenerate. 
Internodes differ from the type of stem described above chiefly 
in their smaller size, but also in the fact that all the nodal tissues 
in addition to that directly concerned in the production of the 
bud has been lost. Apparently for this reason, they disintegrate 
with far greater rapidity than the larger pieces. Only in the case 
of certain of the begonias have records of shoot-formation in inter- 
nodes been met with. Тһе results to be indicated re-emphasize 
the rarity of this occurrence. 
Experiment 27. — The internodes of a series of plants regen- 
erated in a manner similar to ZZeterocentron diversifolium described 
Бу Vóochting,* in that they gave rise to roots at the base, but not 
to shoots.  Internodes which yielded this result belonged to 
Muhlenbeckia platyclados, Phyllocactus, Vitis quadrangularis, Не- 
dera helix and Bryophyllum calycinum. Internodes of a large 
number of other plants decayed without regeneration. 
Experiment 28. — Internodes of Muhlenbeckia platyclados were 
placed in inverted positions in the sand. Оп one pee the 
first trial, roots appeared, but the suspicion arose that it had been 
* Über Organbildung, etc., 72. 
