26 Newcombe, Sensitive Life of Asparagtu plumostcs. 



shoots thus used. If these shoots were vertical when set out in 

 the light, this direction was hehl for from 1 to 2 days, when the 

 deflection to the horizontal position began. II' the Position of the 

 shoots was 45° or more below the vertical when exposure to light 

 began, the shoots invariably rose, reducing this angle by 10° to 

 40° during the lirst day and a half. The following is a represen- 

 tative instance of behavior: 



18) Shoot grown in opaque cover to hight of 66 cm with 

 declination of 30° when set out ander open sky at 7 : 30 A. M'., 

 and shaded from direct sunlight. Uirection maintained for 36 hours, 

 then tip rose 15° — next raorning declined to 30°, but later in 

 day rose again to 15° — 4th day morning declined to 30°, afternoon 

 rose to 15° below vertical — 5th day declined to 35° and unfolded 

 branches — 6th day declined to 65° — 7th day declined to the 

 horizontal position and ceased nutation. 



VII. Behavior of Plants on the Klinostat. 



Inasmuch as the development of diageotropism in normal 

 growth is closely associated with the cessation of elongation of the 

 shoot, it might be thot that revolution on the klinostat might cause 

 a greater than normal elongation. An additional reason for imagining 

 that this might be so is the result of growing the plant in the 

 dark — the produetion of a greater number of internodes and the 

 abscence of a final diageotropic position. When the test is made, 

 however, it is found that revolution of the plant in the light with 

 the axis of the klinostat horizontal causes no more than normal 

 elongation. The shoot ceases growth at the usual size. Altogether 

 10 plants have been revolved on the klinostat to test this question, 

 6 with the axes of the shoots at right angles with the horizontal 

 axis of the klinostat, and 4 with the axes of the shoots parallel 

 with the horizontal axis of the klinostat. In the case of one of 

 these plants, the revolution began before the tip of the shoot had 

 come more than a millimeter above ground; the other shoots were 

 from 1 to 6 cm high when revolution began. No unusual elongation 

 was seen in any of them. 



When revolution of these plants with the axis of the klinostat 

 horizontal is conditioned so as to equalize light, the plant develops 

 with all Orders of branches related to the main axis as in Asparagus 

 offirinale. The aspect of the plant is very different from the usual. 

 Instead of flattened frond, there is formed a central axis with 

 branches growing out from it in several planes, these branches of 

 the first order bearing their branches also in various planes, and 

 finally the needles in brushes filling a hemisphere instead of flattened 

 in a circle like the spokes of a wheel. Except for the needles, 

 all of the branches of these plants grown on the klinostat make 

 angles with the axis from which they arise of about 80° above 

 and 100° below. 



It is interesting to learn that as these plants grow to ma- 

 turity on the klinostat, both main and lateral axes retain their 



