ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
485 
have for their object the protection of the sexual organs and of the 
honey, and the promotion or prevention of foreign pollination ; these 
may be termed gamotropic movements, in contrast to the nyctitropic 
movements, which serve merely for protection from injurious radiation 
at night. 
Movements of the bracts, sepals, and petals, and of the flower-stalks 
for the protection of the ripening fruit, or for the dissemination of the 
fruit or seeds — carpotropic movements. 
The author gives also numerous instances of photo-cleistogamic 
flowers, in which the opening of the flower is prevented by the rapid 
growth of the outer side of the petals, the result of photo-hyponasty ; of 
the nutation-movements of leaves and petals which are caused not only 
by changes in light and temperature, but also by variations in turgidity, 
and of such as are caused by variations in temperature and turgidity 
only ; and of the movements of nutation and irritation in stamens, styles, 
and stigmas. 
The leaves of Marsilea exhibit movements of irritation under the 
influence of concussion, in addition to the more conspicuous sleep- 
movements. The leaves of many Papilionacese exhibit more considerable 
paraheliotropic movements in southern than in northern latitudes, for 
the j)rotection of their chlorophyll from intense sunlight. 
Influence of Heat on the Movements of the Flowers of Anemone 
stellata.* — According to Herr H. Vochting, the flower-stalk of this 
plant, which, before the unfolding of the flower, is bent downwards, 
becomes erect immediately on its opening, bending towards the sun, 
and following its course through the day ; in the evening the plant 
takes up a sleep-position, the perianth closing, and the flower-stalk 
again bending downwards. A careful series of observations convinced 
the author that these successive movements were in no way due to 
changes either in the light or in the degree of moisture, but entirely to 
changes in temperature. Contrary to what takes place in Papaver , the 
movements of the flower-stalk of Anemone stellata are not directly 
dependent on the flower, since they continue even after this has been 
cut off. 
(40 Chemical Changes (including Respiration and Fermentation). 
Formation of Starch from Organic Substances by Leaves.f — As 
the result of a series of experiments with a number of different carbo- 
hydrates and other organic substances, Herr G-. Nadson finds that the 
chlorophyllous cells of various plants (Dicotyledons, Monocotyledons, 
Vascular Cryptogams, and Algae) can in nearly all cases form starch out 
of cane-sugar, dextrose, and dextrin, less uniformly out of milk-sugar, 
glycerin, mannite, and melamprite, never out of inulin, quercite, glycogen, 
gum-arabic, calcium saccharate, or out of tartrates, oxalates, or malates. 
As a general rule, starch can be formed out of substances which contain 
the two radicals of alcohol, CH 2 OH and CHOH, but not out of those 
which contain only one of these elements. 
* Jabrb. f. Wiss. Bot. (Pringsheim), xxi. (1889) pp. 285-97. 
t Arb. Petersburg Naturf. Yer. 1889, 50 pp. See Bot. Centralbl., xlii. (1890) p. 48. 
