1013 



''praoisiren iiiir iiorli iinsci'e Slelltiiiosnahnie zii derselben. Es yei 

 "betont dass wir eiiie iill,ü,eiiieiii «guitige L(")Siiiig dieser Frage iiier 

 "niclit geben wollen noch kcnmen. Unseiei- Ansielit iiacli ist eben 

 "die Fragestellimg iiacli der Rolle der Nebenzelleii in dieser Allge- 

 "meinheit unriehtig, well höchst wahrsclieinlich diese eine von Fall 

 "zn Fall wechselnde ist. Ini AUgeineinen lielilig wird eine ver- 

 ^'mittelnde Stelhingsnahnie sein: Die OefFnnng des Spaltes wird diircli 

 "der Turgor der Schliesszellen selbst bewirkt, die angrenzenden E[)i- 

 "dermiszellen mussen in vielen Fallen ziim Verscliluss niit beiti-agen." 



In J899 Westekmaier ^) published an investigation on sloniata 

 and their accessory apparatus in which he does not deal at all with 

 the question of the antagonism between guard-cells and adjacent 

 epidermal cells. 



In 1902 CoPELAND ^) published a detailed inquii-y into the mecha- 

 nism of the stomata in which he takes the view that the turgor of 

 the adjacent epidermal cells can only play a passive part in bringing 

 about the movement of the stomata. "In stomata, whose outline changes 

 "with their movements, and only in these, the turgescence of the 

 "contiguous cells must be a factor in determining the state of equilibrium, 

 "open, closed, or intermediate. But because the pore closes with excessive 

 "transpiration when turgescence in the leaf is least, because the 

 "contents of the guard-cells furnish a clue to changes in turgor 

 "which is wanting in the neighbouring cells, because some stomata 

 "do not change their outline (surface view) in their movements, 

 "because isolated stomata usually move like those on uninjured 

 "leaves, and because the forms and structures of the guard-cells are 

 "explicable and intelligible on this ground only, the conclusion cannot 

 "be escaped that the turgescence of the neighbouring cells is a 

 "passive factor, the active one being, as Schwendener and his students 

 "have maintained, the turgescence of the guard-cells". 



Haberlandt^) in the last edition of his handbook hardly says 

 anything about this question, but also clearly ascribes very little 

 importance to the turgor of the adjacent cells. The only reference 

 to the antagonism between the guard-cells and the epidermal cells 

 is as follows: "Bei einigen Grasern (Oynosurus echinatus, Aira capillita, 

 "Briza maxima) ist die Zentralspalte auch im turgorlosen Zustande 

 ^'der Schliesszellen, nach Tötung dieser, often. In diesen Fallen miis- 

 "sen also, sofern die Spaltöftnungen überhaupt noch funktionsfahig 



1) Westermaier, üeber Spaltoffnungeii und ihre Nebenapparate. Festschrift fur 

 ScHWENDENER. Berlin 1899. 



2) GopELAND, The Mechanism of Stomata. Annals of Botany XVI 1902. 



3) Haberlandt. Physiologische Pflanzenanatoraie. Dritte Auflage 1904. 



