412 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
be that, with distilled water, the tissues are less fully developed, while, 
on the other hand, they are more strongly lignified. Thus, in a saline 
solution, both the roots and the stem become larger ; the size, both of 
the vessels and of the air-cavities, is increased ; while the walls of the 
former are less strongly lignified. 
Effect of Electricity on Vegetation.* * * § — Mr. Asa S. Kinney records 
the results of a series of observations on the effect on germination of 
a continuous electric current. With a small alternating current of 
moderate frequency and high voltage, there was in all cases an increase 
in the rapidity of germination and elongation of the radicle and hypo- 
cotyl. There was a distinct optimum above and below which the treat- 
ment was less effective, though never injurious. 
(3) Irritability. 
Movements of Swarm-Spores, Antherozoids, and Plasmodes.j* — 
Dr. R. Kolkwitz gives a resume of the literature published during the 
years 1885-1896 under the following heads: — Mechanics of the move- 
ments of Diatoms, Swarm-spores, Bacteria, Antherozoids, Oscillatoriacese, 
Desmidiacese, Gregarinese, Plasmodes, Amoebae, Flos-aquae, Phycochro- 
maceae and Radiolarieae ; the influence on the movements of Light, of 
Chemical substances, of Heat, of Moisture, of Gravitation, and of 
Electricity. 
Gamotropic and Carpotropic Movements.:*: — Prof. A. Hansgirg 
gives a further very extended list of plants in which the parts of the 
flower, or the flower-stalk or fruit-stalk, exhibit movements of curvature 
for the protection of the reproductive organs, or to assist in pollination, 
or to place the fruit in a more favourable position for the ripening of 
the seeds. The gamotropic movements are arranged under the follow- 
ing classes : — (1) plants [in which the flowers or inflorescences open or 
close periodically ; (2) plants with ephemeral or pseudo-ephemeral 
flowers which open only by day or only by night ; (3) plants with non- 
gamotropic flowers which open only once, and remain open until they 
wither; (4) plants with pseudo-cleistogamic and hemi-pseudo-cleisto- 
gamic flowers. 
Of carpotropic movements the following 8 types are recognised : — 
(1) the Arena- type; (2) the Oxalis- type; (3) the Primula-type; (4) the 
Coronilla-type ; (5) the Veronica- type; (6) the Aloe- type; (7) the 
Frag aria- type ; (8) the Aquilegia-type. Special attention is paid to 
the carpotropic curvatures of sepals and bracts. 
Further observations are also described on nyctitropic and para- 
heliotropic movements, on the irritable movements of stamens and 
stigmas, and on irritability in general. 
Ombrophoby of Elowers.§ — By this term Prof. A. Hansgirg de- 
signates the phenomena of curvature by which many flowers protect 
* Bull. Hatch Exp. Station (Amherst, Mass.), No. 43, 32 pp. See Bot. Gazette, 
xxiii. (1897) p. 302. t Bot. Centralbl., lxx. (1897) pp. 184-92. 
X S.B. K. Bohm. Gesell. Wiss., 1896, 111 pp. and 1 pi. Cf. this Journal, ante, 
p. 144. 
§ Tom. cit., 67 pp. and 2 pis. Cf. this Journal, 1890, p. 484. 
