Chap. I. TWINING PLANTS. 5 



segment of a circle. After the seventeenth revolution 

 the internode had grown from If to 6 inches in length, 

 and carried an internode IJ inch long, which was 

 just perceptibly moving ; and this carried a very minute 

 ultimate internode. After the twenty-first revolution, 

 the penultimate internode was 2^ inches long, and 

 probably revolved in a period of about three hours. 

 At the twenty-seventh revolution the lower and still 

 moving internode was 8|, the penultimate 3^, and 

 the ultimate 2^ inches in length ; and the inclination 

 of the whole shoot was such, that a circle 19 inches 

 in diameter was swept by it. When the movement 

 ceased, the lower internode was 9 inches, and the 

 penultimate 6 inches in length; so that, from the 

 twenty-seventh to thirty-seventh revolutions inclusive, 

 three intemodes were at the same time revolving. 



The lower internode, when it ceased revolving, 

 became upright and rigid ; but as the whole shoot 

 was left to grow unsupported, it became after a time 

 bent into a nearly horizontal position, the uppermost 

 and growing intemodes still revolving at the extremity, 

 but of course no longer round the old central point of 

 the supporting stick. From the changed position 

 of the centre of gravity of the extremity, as it revolved, 

 a slight and slow swaying movement was given to the 

 long horizontally projecting shoot ; and this movement 

 I at first thought was a spontaneous one. As the shoot 

 grew, it hung down more and more, whilst the growing 

 and revolving extremity turned itself up more and more. 



With the Hop we have seen that three intemodes 



