Chap. 1 



ASl'AEAGUS. 



61 



the same general direction, but in a slightly zigzag manner, 

 until it became upright. On the following morning it changcci 

 its course completely. There can therefore hardly be a doubt 

 that the plumule circumnutates, -whilst buried beneath the 

 ground, as much as the pressure of the surrounding earth will 

 permit. The surface of the soil in the pot was now covered with 

 a thin layer of very fine argillaceous sand, which was kept damp; 

 and after the tapering seedlings had grown a few tenths of 

 an inch in height, each was found surrounded by a little open 

 space or circular crack ; and this could be accounted for only by 

 their having circumnutated and thus pushed away the sand on 

 all sides; for there was no vestige of a crack in any other part. 

 In order to prove that there was circumnutation, the move- 

 Fig. 48. 



Asparagus officinalis : circumnutation of plumules with tips whitened and 

 marlvs placed beneath, traced on a norizontal glass. A, young plumule ; 

 movement traced from 8.30 a.m. Nov. 30th to 7.15 A.M. next morning ; 

 magnified about 35 times. B, older plumule ; movement traced from 

 10.15 A.M. to 8.10 P.M. Nov. 29th ; magnified 9 times, but here reduced 

 to one-half of original scale. 



ments of five seedlings, varying in height from -3 inch to 2 inches, 

 were traced. They were placed within a box and illuminated 

 from above; but in all five cases the longer axes of the figures 

 described were directed to nearly the same point ; so that more 

 light seemed to have come through the glass roof of the green- 

 house on one side than on any other. All five tracings re- 

 sembled each other to a certain extent, and it will suflBce to give 

 two of them. In A ^Fig. 48) the seedling was only 45 of an 



