Vol.. 6, 1920 
PHYSIOLOGY: H. S. REED 
405 
{Xd^/nY^' of these results is 3.4 cm. The agreement, therefore, is satis- 
factory. 
Comparing the calculated values of x with the observed, it will be seen 
that there are 16 deviations on the + side and 12 deviations on the — 
side. In figure 2, the upper curve shows the calculated course of the 
growth process alongside of the actual observed values. 
The writer is fully aware that equation (6) is somewhat cumbersome. 
Its claim for consideration is, however, an important one, viz., it satis- 
factorily represents the observed facts. In the present state of our 
knowledge it seems advisable to use a formula like the above rather than 
a simpler type which might not so accurately represent the actual growth 
Growth of apricot shoots. 
IS iO 
Time in weeks 
FIG. 2 
curve calculated from 
X = 210[1 - e~-^^^ + 19.1 [e-^^^^ cos -/] 
- curve calculated from 
- = 19.95 g--095 (/-^ i)_i9,i ^-.055^(0.055 cos - 1 + - sin -t) 
dt 14 14 14 
O O O, observed lengths of shoots. 
A A A, observed increments of shoots. 
□ □ "adjusted values" (5). 
reaction. Future studies may show that a satisfactory equation of simpler 
form exists. 
A consideration of equation (6) shows that we are here dealing with a 
homogeneous reaction, consisting of two unimolecular reactions, the first 
of which is always positive, and the second alternately positive and 
negative. 
