142 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
as increased conspicuousness, a guide to tlie visits of insects, tlie formation 
of nectar, &c. Organs may undergo actual transformation in the course 
of their development. The author attributes these transformations to an 
inner force originating in the protoplasm. 
Influence of Nutrition on the Colour and Sex of Flowers.* * * § — As the 
result of experiments on Dahlia variahilis and Petunia hyhrida , Herr 
F. Hildebrand finds that the nature of the soil has a considerable 
influence on the colour of the flowers in hybrids, a more or less diffused 
etiolation being the result of a diminished supply of nutriment. The 
monoecious or dioecious condition of Busciis aculeatus appears also, in 
part at least, to be determined by conditions of growth. 
(2) Nutrition and Growth (including: Germination, and 
Movements of Fluids). 
Rontgen Rays and Vegetation.}* — Herr N. J. C. Muller asserts that 
ordinary sunlight contains no Rontgen rays ; their presence not being 
indicated either by the help of photographic reagents or by any helio- 
tropic effect on the growth of Lepidium sativum. 
Influence of Electricity on the Growth of Plants.}; — As the result of 
a series of experiments made on aquatic plants, M. M. Thouvenin has 
arrived at the conclusion that a continuous electric current promotes 
assimilation by accelerating the decomposition of carbon dioxide by the 
plant. 
Influence of Electricity on Germination.§— From a series of experi- 
ments on different seeds, Sig. G. Tolomei comes to the conclusion that 
currents of electricity of great frequency exercise an injurious effect on 
the vitality, and consequently on the germination, of seeds ; and that the 
intensity of this injurious action varies with the species. 
Germination of Barley.] — Pursuing his investigations on the 
chemical changes which take place during germination, Herr J. Griiss 
states that in barley the solution of the cell-walls of the endosperm 
commences in the neighbourhood of the scutellum, and advances to- 
wards the apex of the grain, most actively in the outer part : a small 
portion at the apex usually remains intact. The cell-walls are not 
dissolved, but corroded ; they are rendered permeable to enzymes by 
alloolysis. Congo-red stains intact cell-walls an intense red, while those 
that have been affected take only a slight light-red tint. The starch- 
grains are attacked only after the corrosion of the cell-wall, and first in 
the neighbourhood of the scutellum. Diastase may be produced sponta- 
neously in the endosperm of ungerminated seeds from which the embryo 
has been removed. 
Influence of Nitrogen on the Formation of Roots.! — As a result of 
a series of experiments on the growth of different plants in soils contain- 
* Ber. Deutsch. Bot. Gesell, xiv. (1896) pp. 327-31. 
f Tom. cit., Gen.-Versamm.-Heft, pp. 66-72 (1 pi.). 
j Bev. Gen. de Bot. (Bonnier), viii. (1896) pp. 433-50 (9 figs.). 
§ Malpighia, x. (1896) pp. 493-511 (3 figs.). 
|| Wochenschr. f. Brauerei, 1896, 4 pp. and 1 pi. See Bot. Centralbl., lxviii. 
(1896) p. 323. Cf. this Journal, 1896, p. 652. 
^1 JB. d. Versuchs-Stat. in Wadensweil, iv. pp. 48-52. See Bot. Centralbl., lxviii. 
(1896) p. 298. 
