J 80 



If the terminal hud or a part of the main-axis he cut off, tiie 

 lower lateral hud or hiteial slioot will develop more strongly lliaii 

 it woidd otherwise have «lone, and will at the same lime lieiid 

 upwards until it assumes (he position entirely, or almost, of the 

 inain-axis; amputation thus causes an accelerated growth as well as 

 strong geotropic heiiding. 



The absolute relation between the two, so striking here, is simply 

 explained now by the circumstance that both are dejiendent upon 

 stimulation of the static apparatus. 



If, for instance, the almosi horizontal lateral axis of Araucaria, 

 after amputation of the terminal hud, gradually assumes a \ertical 

 position, this might have been preceded by shifting of tiie apparatus 

 from the lowest longitudinal wall to the basal transverse wall, i. e. 

 a shifting in the direction of the wound. Tangi. ') and Nesti^er ') 

 now lia\'e demonslrated that the result of a wound is that in the 

 neighbouring cells the protoplasm tends to accumulale in the direc- 

 tion of the wound; if it be that the static apparatus had a share 

 in this shifting, this alone could be a reason for the appearance of 

 the negative-geotropic movement. 



It might be mentioned in this connection that, according to 

 Richter '), even a plant of so much more simple structure as C/(a?'«, 

 shows the same phenomenon, namely, that after amputation of the 

 terminal hud, the adjoining lateral luancli grows out more quickly 

 and bends sharply upwards. 



Amputation of the radicle has not the same effect upon the side- 

 roots of the first oi'der; .Sachs ^) has demonstrated that the lateral 

 roots already present show no change in position, but that the 

 after the amputation new formed lateral roots grow out in a more 

 vertical direction, thus showing rather an influence upon the position 

 of the apparatus in the newly formed cells instead of producing a 

 shifting in those already present. 



c. The static a[)paratus changes its position continually. 



When the static apparatus is at rest in any organ, that organ 

 assumes a certain position of equilibrium; in the case of a continual 

 autonomic shifting, on the contrary, the organ will never arrive at 

 a position of equilibrium and therefore never be at rest. Such 

 ceaseless movements are known in the nutations and in tiie 

 twining of plants. 



1) Sitzangsber. der K. Akad. der Wissensch., Wien, 1 Abt., 1884. Bd. 90, p. 25. 



2) Ibidem, 189S, Bd. 107, p. 708. 

 S) Flora, 181)4, p. 416. 



■*) Arbeiten des botan. Inst, zu Wiirzbiirg, Bd. 1, p. 622. 



