LEAVES WITH REGABD TO EIGHT. 



441 



{Experiments ivith the Klinostat.) 

 Experiment 3 (Table XII.). — The plant was grown in a small 

 pot out of doors, and was a seedling with a woody stem 9 centim. 

 hio-h with a bunch of eight leaves budding out at the top and other 

 (older) leaves growing on the woody stem. On April 26th, 4 p.m., 

 it was fixed in the zenith position at a north window, the large mirror 

 being in front as above described. The angles in the following 

 table were generally taken by removing the spindle of the klino- 

 stat with the plant attached, and measuring the angles at which 

 the leaves stood when the plant was in the normal position. 



Table XII. 





i. 



ii. 



iii. 



Date. 



Lamina. 



Lamina. 



Lamina. 



April 26, 1 



4 P.M. J 



o 

 + 3 



o 

 + 15 



O 



+18 



April 26... [ 



After the above measurements were taken, 



it was placed in the zenith position. 



April 28, \ 

 8.20 a.m. J 



-14 



-13 



4- 3 



April 30, \ 

 8.40 a.m. J 



-21 



-25 



- 7 









May 4, \ 

 3.6 p.m. ( 



-57 



-70 



-35 



It is clear from this experiment that the leaves of the cherry 

 are not able to remain even approximately at right angles to 

 the light when on the klinostat ; for it will be seen that all the 

 three leaves curved strongly towards the stem. It appears that, in 

 order to remain in the diaheliotropic plane, some force is wanted 

 to oppose the tendency of the leaves to curve towards the stem. 

 Therefore the cherry behaves in a markedly different manner from 

 Banunculus Ficaria ; for the latter is able to keep its leaves in the 

 diaheliotropic plane when grown on the klinostat, and without 

 the assistance of apogeotropism to act as an opposing force. 



Experiment 4 (Table XIII.).— The same plant was next, May 

 4th,3.10 p.m., removed from the klinostat and placed in the normal 

 position in the dark ; and by the following morning (May 5th) the 

 leaves had risen apogeotropically. 



