766 



we must take up also the subject of anaesthetica. The favorable results 

 which can be obtained, especially in the early forcing of lilacs, by a proper 

 use of this method are certain beyond doubt ; but with an incorrect use dis- 

 advantageous results become noticeable. The action of ether, chrom-ether 

 chloroform, nitrous oxid, morphine, cocaine, etc., as proved by repeated 

 experiments, consists in retarding the complete development of protoplasmic 

 activity. If, in this, the protoplasm undergoes a continued injury to its 

 physical or chemical structure, death follows ; otherwise, the plant gradually 

 returns to the normal activity.^ Naturally the effect depends upon the con- 

 dition of the protoplasm. Thus, Coupin- has proved that even an atmos- 

 phere saturated with chloroform and ether can exert no influence on the 

 protoplasm of seeds in a dormant stage. If, however, their life activity has 

 been aroused by moistening very small amounts (.00037) are enough to 

 cause injury. Yet the figures given here should not be considered as a 

 standard, for aside from the individuality of the species even plants of the 

 same species can develop a different power of resistance by self adjustment. 

 Thus, for example, Townsend^ states that spores of Mucor and Pcnicillium 

 ripened under a strong ether atmosphere germinated and produced spores 

 just as quickly as when they had germinated in an atmosphere free from 

 ether. The same observer mentioned that here and in other poisons very 

 weak doses act as a stimulus and shorten the period of germination, while 

 stronger doses are injurious. 



The observations of Markowine"* give an insight into the kind of action. 

 He draws the conclusion from his experiments that, in the long continued 

 action of anaesthetizing vapors, respiration becomes considerably increased. 

 He found that, under the influence of alcohol vapor, the respiration of 

 etiolated plants was increased more than one and a half times ; ether acted 

 still more strongly. 



We may assume here a specific response to stimulation. Behrens"' also 

 holds this theor}\ He would like also to consider as a response to stimula- 

 tion the hastened germination of seeds after mechanical injury which Hiltner 

 ascribes to the facilitated absorption of water. Behrens bases his theory on ex- 

 periments with injured seeds in which the wounded places were covered at 

 once with colophoneum wax. Although the absorption of water by these grains 

 did not seem increased as compared with normal grains, there appeared, never- 

 theless, an appreciable increase of growth. Experiments with filing and 

 other intentional injuries to hard shelled seeds proved, however, that even 

 the mechanical facilitation of the entrance of water favors germination. 



1 Kaufmann, C, tJber die Einwirkung- der Anaesthetica auf das Protoplasma 

 und dessen biologisch-physiologrische Eigenschaften; cit. Just's Jahresber. 1900, II, 

 p. 301. 



2 Coupin, H., Action dos vapeurs anesthesiques sur la vitalite des graines 

 seches et des g-raines humides; cit. Just's Jahresber. 1900, II, p. 301. 



3 Townsend, C. O., Tlie effect of ether upon tlie germination of seeds and 

 spores; cit. Just's Jahresber. 1899, II, p. 142. 



4 Markowine, N., Rccherches sur I'influence des anesthesiques sur la respiration 

 des plantes; cit. Just's Jahresber. 1899, II, p. 143. 



5 Behrens, Bericht d. Grosshorzogl. Badischen Landwirtsch. Versuchsanstalt 

 Augiistenberg- f. d. Jahr. 1906. 



