222 MR. F. DARWIN ON THE CONNECTION 
growth of the normal roots was much greater than that of the 
“cut” ones, But when the growth during 12 h. 10 m. is taken, 
the average growths are as 885 to 73/7, or as 100 to 83. Nor 
did the amounts of geotropic curvature correspond with the inten- 
sities of growth. None of the cut roots were geotropic. No.i. 
was bent at 9 millim. from the apex, so as to be 30? below the 
horizon; but this curvature did not increase. Nos. i, and iii. 
remained horizontal. The two normal roots were clearly geo- 
tropic, i. pointing vertically down, and ii. 607-70? below the 
horizon. The growth of ii. was 54 perc ent. in the 12h. 10m., 
which is less than that of the two cut roots which remained 
horizontal. 
Experiment III. —The roots were marked at 2 millim. and at 
5 millim. from the tip, placed, as before, horizontally on damp 
peat:— 
Cut Roots. 
Length of Percentage Percentage 
measured growth in growth in 
space. 3h. 10m. 3h. 5m. additional. 
millim. 
b ............... 27 3 39 
e ki. 29 3 34 
Busen 2:8 4 44 
IV. ee 24 16 36 
ENEE 26 IN 60 
Average ...... T4 42:6 
Normal Roots. 
EE 29 6 27 
I eode 2:8 11 54 
nic 2:6 10 37 
iY. sees 2:6 11 31 
oe 60 
Average...... 9:5 418 
Here, again, we find that the cut roots grow during the first 
period more slowly than the normal ones; for we have, 
normal : eut :: 100: 78. 
On the other hand, during the second period of growth this state 
of things is reversed, and we have, 
normal : eut :: 100 : 102. 
None of the eut roots were geotropic ; whereas all the normal 
ones were well bent except iii., and this was not one which grew 
especially weakly. 
