( 343 ) 
Botany - "The inadmissibility of the statolith theory of geotropism, 
as proved by experiments of Miss. C. J. Pekelharing. By 
Professor F. A. F. C. Went. 
The statolith theory as formulated by Haberlandt and Stem 
order to explain the perception of gravitational force by plants, has 
led to a whole series of papers in which the authors have attempted 
to advance arguments for and against the theory. It is not my 
intention to discuss these here; it may suffice to say that none of 
them have led to a definite conclusion concerning the question and 
have at most induced Haberlandt (Mmec did not occupy himself 
any further with the matter) to modify the theory several times m 
order to bring it into line with newly discovered facts 
The adherents of the statolith theory suppose that the perception 
of gravitational stimuli takes place in the plant cell in consequence 
of the pressure exerted by starch grains on the protoplasm. We 
may consider it an entirely open question, whether in this case we 
should postulate that the starch grains change their place when the 
orientation of the cell with regard to the perpendicular is changed, 
but in any case we may demand, that the faculty of perceiving 
gravitational stimuli should go together with the presence of Starch 
grains. Hence it is intelligible that both Haberlandt and Nemec tried 
to make the starch disappear from the sensitive parts, the former 
with the aid of low temperatures, the latter by imbedding the objects 
in plaster of Paris. They were successful in this; the power of 
perceiving gravitational force disappeared with the starch and returned 
when the starch was regenerated. These experiments did not, however, 
furnish a conclusive proof, because 
uncertain whether the 
treatment which brought about the disappearance of the starch, did 
not also affect adversely the reactivity of the protoplasm. 
A detailed discussion of these experiments seems superfluous, on 
account of what follows. In experiments on the perception of gravi 
tional stimuli Miss G. J. Pekelharing attempted in my laboratory 
to bring about the disappearance of the starch from the geotropica y 
sensitive parts by a different method from that employed hitherto. 
In so doing she obtained important results of which I wish to give 
here a preliminary outline. . . 
of Plum') had shown that by means of aluminium 
salts it is possible to eliminate stareh from living cells, both from 
Aluminiumsalzen auf das Protoplasms, Flora, 
l ) M. Fluri, Der Einfluss 
Bd. 99, p. 81, 1908. 
