250 BOTANICAL GAZETTE [octoBER 
on three more only on the middle third; on three more only on the 
lower third; while all the buds were left on the last three. These 
were all placed horizontal in moist air. On the last three mentioned 
only the upper buds formed shoots; and at the same time most of 
the buds, especially the uppermost ones, started on all the other 
pieces. Many tests showed that any bud at any place along the 
stem would develop if the buds above it were prevented from doing 
so. Here again, it is not a question of nutrition or water, for the 
stems and buds are filled with reserve food, and in a constant spray 
(in which the experiment was repeated) there can be no lack of 
water. 
Whatever the influence of the growing buds may be, it is felt only 
on those below them, and not on the buds above them (that is, toward 
the apex of the axis). In the experiment just mentioned, in whi 
the upper buds were inhibited by hydrogen, those below had gotten 
a good start and were forming shoots, but when the hydrogen was 
removed, the upper ones developed as usual. 
Experiment 45.—A piece of Salix stem, 30°" long, was placed 
so that the 12°™ in the center was in a continuous spray, and the 
two ends in quite dry air. The buds in the central portion swelled 
up and burst open before the others showed any signs of swelling. 
The whole piece was then placed horizontal in moist air. The buds 
at the apical end soon enlarged and developed shoots; but those at 
the lower part did not. ‘These central buds, while able to prevent 
the buds below them from developing, had no influence on those 
above them. Finally, all the young shoots and buds were cut off 
from the upper two-thirds of the piece, and the upper ones 0? the 
basal third promptly started. : 
If the entire piece is surrounded by the same conditions, the 
shoots all appear at the apical end; but by placing the basal end in 
water and the rest in dry air, the buds in the water or close to the 
surface start first; but soon the upper ones commence to m0 
apparently indifferent to those below them; and as the young — 
increase in size, those below become less vigorous and are pi 
finally suppressed. Other experiments of a kindred nature migh : 
be mentioned, but these will suffice to indicate that the developme 
of the buds at any region along the stem tends to suppres? wt 
