'_»i i Newcombe, Sensitive Life of Aapwragus ptumosta 



by digging the earth away from the base of the aerial shoots tili 

 unfolding buds were found on the rhizome. None of these buds 

 were selected for experiment anless they had Lain beneath at least 

 a centimeter of earth; many of them were 2 cm below the surface. 



To shield these devcloping shoots from the light, concs were made 

 of black cardboard, the smaller end 3 to 4 cm in diameter the 

 Innrer about 15 cm in diameter. These cones were about 50 cm 



in night to Start with, and were easily extended to any desired 

 hight by adding sections. To cover the young shoot, the earth 

 was cleared away about it for a space large enough to receive 

 the small end of the paper cone. The pot was fchen set on a 

 heavy wooden base to whose sides had been fastened 2 upright 

 wooden rods to serve as Supports to the paper cone. The cone 

 was then inverted over the bud on the rhizome and tied to the 

 upright rods. About the base of the cone the earth was packed 

 firmly to a depth of one to two cm so as to exclude light. The 

 upper, larger, end of the cone was covered with several layers of 

 black cloth, aud over the cloth was pressed down a cap of black 

 cardboard. These covering cones were very seldom removed during 

 the progress of the experiment. Provision was made for Obser- 

 vation by cutting Windows in the sides of the cones, closing the 

 Windows with wrappings of black cloth or by partial cones of 

 black paper sliding over the covering cones. A good many ob- 

 servations conld be made by removing the cap over the upper end 

 of the cone, and using a mirror to throw light into the cone. The 

 assimilating shoots were left to continue their work outside the 

 cones. 



Altogether 20 shoots never exposed to light havc been raised 

 within these cones to hights varying from 30 cm to 200 cm, and 

 observed for nutation. The general result, as far as the assumption 

 of the diageotropic position is concerned, has been the absence of 

 a fixed diageotropic position. Invariably the covered shoots have 

 begun to lower their tips about the time they reached the hight 

 of the next youngest shoot outside the cone; and invariably, if the 

 experiment was continued long enough, the tip has risen again 

 betöre reaching the horizontal position, and continued growing 

 erect for a period of days or weeks, to decline again later to 15° 

 to 45° from the vertical, there to remain for a few hours to a 

 few days, and again to assume the erect position. After one of 

 these shoots had reached a hight of a meter, more or less, its 

 form was that of a straight cord except for an oblique portion, 

 here and there, of one to a few centimeters in length, these oblique 

 portions marking the positions at which the tip had remained for 

 several hours to several days at an angle between the vertical 

 and horizontal. 



The following typical examples of detailed behavior will serve 

 to put the case more precisely before the reader: 



1) Covered shoot when 4 cm tall declined 15° for 2 to 3 

 hrs. — erected and grew vertical 30 days — then declined 35°, 

 now 31 cm tall — after 1 day vertical again — after 12 hrs. 



