Newcombe, Sensitive Life of Asparagus plumosus. 
27 
negative geotropism and positive heliotropism. At a time when 
branches of the first and second Order are well unfolded, if the 
revolution of the klinostat is stopped at night, 3 or 4 hours suffice 
to produce npward curves at the tips of the main axis and branches. 
If the revolution is so carried out that the access of light is not 
equalized, the tips of the main shoot and branches will bend toward 
the stronger light, These results are wholly different from what 
one sees in plants in normal development; for in them main axis 
and branches are diageotropic as soon as the primary branches 
begin to unfold. 
It has been shown in the work of Miss Conover, as well 
as my own, that the diageotropic axis of Asparagus is in a position 
of equilibrium however it may lie in the horizontal plane; and the 
same is true of the branches. Why then should this plant not 
develop diageotropism when revolved on the klinostat? Suppose that 
the plant is so revolved that its main axis is parallel with the 
horizontal axis of the klinostat. The main axis is always horizontal, 
bnt in spite of this it remains negatively geotropic. And in the 
same conditions of revolution the branches of the first Order might 
place themselves in the horizontal position during _ revolution by 
bending forward or backward, parallel with the main axis. 
Suppose, on the other hand, that the plant is fastened to the 
horizontal axis of the klinostat with the axis of the plant at right 
angles to the klinostat axis. In this position, some of the branches 
of the first order would be always in the horizontal direction if tliey 
merely grew ont at right angles to the main axis. The main axis 
might place its tip in the horizontal (diageotropic?) position by 
merely turning 90° to the right or left of the direction of its older 
part. The evidence, however, is conclusive that diageotropism is 
not at all developed during revolution on the klinostat. 
As the development of diageotropism has been detailed above 
for shoots placed in light after being raised in the dark, so the 
same process conld be followed for shoots developed on the klinostat, 
But on the klinostat, main axis and branches hasten to their fixed 
Position, while in the dark they make slow progress on their 
journey. Thns the development of diageotropism in plants raised 
to full maturity on the klinostat cannot be demonstrated by changes 
for which growth furnishes the evidence. The best that can be 
done is to remove such plants from the klinostat before they have 
wholly completed their growth. This has been done in the case 
of 2 pots with 5 shoots. The result was for the first one or two 
days a negatively geotropic elevation of the tips of the branches, 
followed after 3 days by a depression to the horizontal. The tip 
of the main axis also goes to the horizontal. The older parts of 
main axis and branches, which have unfolded in multiradial arran- 
gement, retain this arrangement permanently, giving to the plant 
a very odd appearance. 
