1898] CURRENT LITERATURE 365 
R. J. WIESNER has published * a short paper on He/iotropism produced 
by di oe daylight. In this paper he lays emphasis upon the fact that 
although the plant parts possess often an enormous capacity for heliotropic 
reaction, they always react to the strongest light, although illuminated by 
diffuse light and, therefore, impinged upon by rays from all sides. It thus 
comes about that the heliotropic organ places itself so as to divide sym- 
metrically the area from which the light comes. The immediate cause of 
this is to be found in the fact that the direction is dcveniioes by those 
impulses which are not counteracted by exactly equivalent impulses.—C. R. B. 
A PAPER by Hermann Barth has been running for some weeks in the 
Botanisches Centralblatt entitled Studies upon the micro-chemical recognition 
of alkaloids in commercial drugs. Barth finds the alkaloids in all parts of 
the drugs; as for example, in the pericarp of Conium maculatum, in the 
seed coats in Peganum Harmadla and Colchicum autumnaie ; in endosperm 
of Areca Catechu, in both endosperm and embryo of Aconitum Napellus, 
and in the embryo alone of Physostigma venenosum. He concludes from the 
occurrence of the alkaloids that it is to be expected that their functions must 
be very various. When they occur in the periphery of the plant organs as 
excretions it is reasonable to suppose that they are then protective substances 
against the eating of such parts by animals. Those occurring in the endosperm 
and embryo serve, according to Heckel, as reserve foods. In most cases, 
however, it appears to be beyond doubt that the alkaloids are to be considered 
excretions, as has been commonly believed. Some useful reactions for the 
recognition of alkaloids are described.—C. R. B 
Dr. A. NESTLER has presented to the Imperial Academy of Sciences in 
Vienna a memoir on “ The traumatropic movement of the nucleus and proto- 
plasm.” A summary of the results as given in the Botanisches Centralblatt 
76:43. 1898 is as follows: The different orientation of the nucleus and 
yledons, and alge, and occurs in like fashion in leaves, stems, and roots. 
The orientation exhibits itself in a few hours after wounding by the move- 
ment of the nucleus and protoplasm close to that wall which is nearest the 
surface of the wound. The maximum stimulation was observed in most cases 
after two or three days. The return of the nucleus and protoplasm to their 
normal position is less definite. In some cases it was observed after five or 
six days, in other cases they appeared to remain fixed even in the intact cells 
immediately bounding the wound. This transposition, which according to 
Tangl may be designated as traumatropic, cannot be explained upon mechan- 
ical grounds, but seems to be a peculiar stimulation movement, not more 
exactly definable, which is connected with the living protoplasts. The trans- 
*S Berichte d. deuts. botan. Gesells. 16:1 58-163. 1898. | 
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