1895.] The Symbiosis of Stock and Graft. 617 
In the middle of June, segments were removed from old 
roots, then producing blossoms, and were inserted into young, 
actively-growing roots, only recently developed from the seed. 
There was union of tissues but no increase in circumference, 
no radial growth. When these inserted pieces were examined 
the following winter they were, unexpectedly, found full of 
sugar. The cells bore abundant plasma, fine nuclei, and 
seemed to be in good condition, although at the time of their 
insertion they had given up the greater part of their reserve 
materials. The only possible conclusion is that the root 
inserts had formed new cane sugar out of the materials 
brought to them by the young roots. Old beets were set into 
young roots and in this way also their life was prolonged, the 
_ old parts dying only a little earlier than the young roots. In 
this case they showed no such quantity of sugar. Inasmuch 
as these old roots did not increase in thickness in spite of their 
good nourishment by the young roots it might be inferred 
that they are not capable of it, but such an inference would be 
wrong. Segments of old roots taken in the middle of March 
and inserted into the basal parts of panicles in rapid develop- 
ment showed a marked growth, what the author calls,—“ ein 
sehr auffallendes Verhalten.” They began a new process of 
development, grew up above the surface of the stem on a level 
with which they were originally inserted, and ended by form- 
ing swellings of various sizes and shapes. When the piece of 
reot was inserted upside down it was swollen at the upper end, 
when it was inserted right end up the swelling was at the 
lower end. Thestem around the insert also finally enlarged, 
sometimes only above the insert, sometimes also at both sides. 
The growth of these root-inserts was very remarkable. Under 
normal conditions the same pieces would have made no growth 
whatever. Planted in the blossoming stem they began to 
grow, and this growth was so energetic in some cases that the 
pieces increased to several times their original volume. Dr. 
Véchting is in doubt as to the cause of this behavior, but 
concludes from it that there is no necessary relation between 
growth and the storing of sugar since he found these growths 
very poor in sugar although the cells appeared to be active. 
