[Vor. 5 
226 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
stamens of Berberis lost their sense of irritability in vapor 
of acetic or sulphuric ether. Leclere (753), also studying 
Mimosa, noted a like loss of irritability, with subsequent re- 
covery when the dose was not excessive, and concluded that 
plants possessed a nervous system analogous to that of 
animals. Loss of irritability varied with light conditions, 
being accelerated in direct sunlight. Kabsch ('61) noted that 
the periodic movement of the leaflets of Hedysarum gyrans 
L. was inhibited by ether and by chloroform and that these 
vapors were lethal in their effect except in minimal doses of 
the former. Mimosa pudica was still a favorite object of 
study, indicated by the work of Blondeau (’67), who con- 
firmed Leclere and came to similar conclusions, and by the 
observations of Bert (’67), who concluded that the paratonic 
movements alone were affected by etherization. Pfeffer (’73) 
did not subscribe to this view, since he found that sleep move- 
ments also were suspended by such treatment. 
Carlet (’73) observed a retardation in nutation of the 
anthers of Ruta when subjected to ether or chloroform, al- 
though movement was not completely inhibited. Under the 
influence of the anaesthetics the pollen sacs did not open. 
Heckel (’73) found that stamens of Berberis lost the power 
of irritability in a chloroform atmosphere, while those of Ruta 
were unaffected, and he supported Bert’s view of two classes 
of plant movements—spontaneous and induced.  Heckel's 
observations along this line (’74, 748, ’74, ’74°, 7744, 74%) 
led him to conclusions regarding the seat of response to 
anaesthetics which Pfeffer (’75) has criticized as based on 
errors of technique and misinterpretation of factors involved. 
A later study by Heckel (’76) of Drosera and Pinguicula was 
concerned with variations produced by different doses of the 
anaesthetics. Darwin (’75) studied the effect of ether and 
chloroform upon the movement of the tentacles of Drosera, 
noting loss of irritability and subsequent recovery when re- 
stored to normal conditions. The classic experiments of 
Bernard (’78) also included the response of Mimosa to 
anaesthetics. 
