40 
Newcombe, Sensitive Life of Asparagus plumosus. 
However, tho the shoot at its earliest origin predestined to be a 
short non-twiner with horizontal tip, and the shoot predestined at 
its origin to be a twiner may be the same length, meters long, in 
the dark, may look alike and behaye alike, the one is still in its 
inner capacity a non-twiner and the other a twiner, as subsequent 
exposure to the light demonstrates. 
Lateral buds fail to unfold in the dark, and this may be 
regarded as an exemplification of the principle of Conservation. 
The failure of the needles to attain their full size in the dark may 
be referred to the same dass of phenomena as the stunted growth 
of leaves in the dark, since the needles are the assimilating organs. 
The biological significance of the horizontal bend of the npper 
third to a half of the non-twining normal shoots is not easy to 
perceive. If one were acquainted with the native environment of 
the plant the task might be easier. None of the benefits assigned 
to similar behavior on the part of Hedera helix , Tropaeolum, Cu¬ 
curbita, Glechoma, Vinca and others will answer for Asparagus, 
for the reason that immediately on taking the horizontal position, 
Asparagus ceases to grow in length. If one observes a potted 
plant with 6 to 12 non-twining shoots he sees that the horizontal 
portions of these shoots are in stories, one above another, the 
oldest below and the last formed the uppermost. The shoots in- 
terfere very little with one another, their arrangement in stories 
leaving horizontal spaces between the stories of fronds. This ar¬ 
rangement also can hardly cause sufficient shade to reduce the 
carbon-assimilation of the lowest story of shoots, for the fineness 
of the members of the branching System and their distance apart 
allow abundant light to penetrate to all shoots. But if the shoots 
grew erect, there would probably also be sufficient light tho the 
branches of the shoots would be crowaed more closely together. 
If the plants grew closely together in beds, it would seem as tho 
the horizontal position would cause as much crowding as the ver- 
tical. Inasmuch as in nature we may suppose the direction of the 
plane of the diageotropic curve to be usually determined by the 
positive heliotropism of the shoot, it might follow that the shoot 
would receive more light in the horizontal position, because of 
shading from above, than tho it grew erect. 
Suminary. 
1. In form and behavior, Asparagus plumosus var. nanus, 
possesses 3 kinds of aerial shoots: 1) Seedling shoots which grow 
to a length of 10 cm to 15 cm, bend their terminal 3 cm to 5 cm 
into a plagiogeotropic position, while the branches not needles 
show a weak form of plagiogeotropism, and the needles are almost 
indifferent to gravitation; 2) non-twining shoots from rhizomes which 
attain a length of 10 cm to 60 cm, bend the upper one-third or 
one-half of the shoot to the horizontal, while branches of all Orders 
