under the Influence of Injuries . 5 1 9 
could be detected in the rate of growth of either root or shoot, 
but during the following nine days the rate of growth of the 
roots was distinctly retarded, while the rate of growth of 
the shoots was just as distinctly accelerated, though not to 
the same extent. 
When leaf-tips were cut off as in Table V, the growth of the 
leaves cut was accelerated if the growing zone was not injured. 
In Series I, Table V, the acceleration began after the first 
twenty-four hours after injury, and continued for five days, 
i. e. during the whole growth of these leaves of the seedlings. 
Table VI. 
Growth of shoot after one leaf was removed. 
Series I. j a— One leaf removed. 
Phaseolus. ( b. — Control. 
Temperature, 23 0 (constant). 
Series. 
Average 
original 
length 
of shoot 
of twelve 
seedlings. 
Average 
normal 
rate of 
growth 
of shoot. 
Average 
growth 
of shoot, 
1st period 
after 
injury. 
Average 
growth 
of shoot, 
2nd period 
_ after 
injury. 
Average 
growth 
of shoot, 
3rd period 
after 
injury. 
Average 
total 
growth 
of shoot 
after 
injury. 
P. 
24 hrs. 
24 hrs. 
96 hrs. 
192 hrs. 
312 hrs. 
I. 
a. 
164 mm. 
9 mm. 
22 mm. 
104 mm. 
66 mm. 
192 mm. 
b 
162 „ 
9 >> 
17 ,, 
63 „ 
3i „ 
ITT ,, 
In Series II a shows a slight retardation after the first 
twenty-four hours followed by acceleration, while b shows 
continuous acceleration after the first twenty-four hours, 
returning to a normal growth after about nine days. 
The effect of removing one of the leaves from young shoots 
was next investigated. For this purpos z Phaseolus multiflorus 
was found to give very satisfactory results. Table VI shows 
that the acceleration in growth began within twenty-four 
hours after injury, and continued for about thirteen days, 
showing a total acceleration of more than 70 °/ o of the normal 
growth. 
