STUDIES IN PLANT REGENERATION 207 
Muhlenbeckia platyclados is well suited for the first purpose 
because of the ease with which the regions concerned in bud-pro- 
duction can be removed. The stem is a flat jointed organ with- 
out functional leaves in the adult condition, but with scales occur- 
ring in two orthostichies at alternating edges of the septa. From 
these regions roots appear when parts of the stem are planted. 
There are, however, no “root buds” in the sense in which the 
words are used for willow and poplar twigs. 
Experiment 14.— Oblique cuts were made above and below the 
scale-bearing portions of the nodes so as to excise these together 
with any rudiments which might be present. The stems 
were then cut into pieces on October 29, 1905, and 
planted. On December 31, all had formed a slight 
callus on the basal cuts and roots had grown out from 
these. In one case a wound had been made in the 
lowest internode, and also a longitudinal slit just above 
the first node. From both of these regions additional 
roots appeared. Cuttings of this sort remained alive and 
healthy for over sixteen months and produced a richly- 
branched root-system, but no new shoots (Fig. 6). 
During this time no change in form or secondary thick- 
ening of any kind took place. This 
is all the more unusual, in that, as will 
be seen later, when a single bud was 
left on the piece, such thickening was 
ку жейде. . Fic. 6. Stem of Muhlenbeckia 
i Exp ermment 15. — Eleven p platyclados from which the buds 
similarly cut were planted in ап in- were cut away. It regenerated 
verted position. Seven of these failed only roots. 
entirely to root. The others pro- 
duced a few roots, but never from the cut end of the internode. 
In these the roots came from the morphologically upper diagonal 
cut. The inverted pieces, probably because they had fewer roots 
also dried up after several months without having formed shoots. 
Experiment 16.-- To determine how far inward from m 
corner of the node the root and shoot-forming “ impulse 
extended, longitudinal slices of from 2 mm. to 4 mm. were cut from 
one edge of pieces from whose opposite side the scale-bearing 
