84 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
B. Physiology. 
Cl) Reproduction and Embryology”. 
Fertilization of Claytonia, Phacelia, and Monarda.* — Mr, J. C. 
Willis lias investigated the mode of pollination in two species of Clay- 
tonia , live of Phacelia , and three of Monarda, and describes the changes 
which take place in the position of the organs concerned. 
Claytonia alsinoides and sibirica are both adapted for cross-pollination 
by insects ; but self-pollination may sometimes occur in the later stages 
by the agency of sleep-movements. 
All the species of Phacelia examined are proterandrous. P. tana - 
cetifolia and divaricata have small inconspicuous flowers, which are 
apparently as a rule self-pollinated. P. Whitlavia, Campanularia , and 
Parryi have larger and more strongly proterandrous flowers, and are 
better adapted for cross-pollination. 
Monarda didyma, halmiana, and Jistulosa have strongly proterandrous 
flowers, adapted for the visits of macroglossate Lepidoptera, though 
they may occasionally be self-pollinated during the movements of the 
stamens. 
Germination of the Pollen of Vinca major. t — Dr. C. Acqua states 
that the pollen-grains of this plant germinate readily in about an hour 
in a 20 per cent, solution of sugar at the ordinary spring temperature. 
The apex of the pollen-tube is apparently formed entirely of hyaline 
protoplasm; the region of microsomes is lower down. At the com- 
mencement of germination the tube appears to be filled with non- 
granular protoplasm. The formation of new cell-wall takes place in the 
same way as Buscalioni has observed in other plants, and the author in 
the hairs of Lavatera J ; but the larger microsomes appear not to take 
any direct part in the process ; they probably break up into smaller 
bodies in the apical region ; and these, interspersed among layers of 
hyaline protoplasm, are transformed into the substance of the cell-wall. 
Dimorphism of the Flowers of Convolvulus arvensis.§ — M. C. 
Schilbersky points out the two forms of flower of this plant, one with 
longer, the other with shorter filaments. Both kinds of flower are self- 
pollinated by the aid of small Coleoptera, or cross-pollinated by Hymeno- 
ptera and Diptera. In the short-stamened flowers there is great 
abundance of fungus-hyphae, which the author regards as belonging to 
an undescribed species which he names Thecamphora Convolvuli. 
(2) Nutrition and Growth (including- Germination, and Movements 
of Fluids). 
Influence of the Solar Rays on Growth. || — M. G. Landel records a 
number of observations on plants both in nature and under cultivation. 
He finds the effect of a varying intensity of the solar rays to be the 
same in kind, though varying in intensity, in different plants, both as 
regards the number of flowers and the production of the red pigment. 
In some plants the pigment is well developed in the shade ; in others, 
* Journ. Linn. Soc. (Bot.), xxx. (1893) pp. 51-62 (1 pi.). 
t Bull. Soc. Bot. Ital., 1893, pp. 373-8 J See this Journal, 1893, p. 752. 
§ Jub. Gedenkb. K. Ungar. Naturw. Gesell., 1892, pp. 623-34. See Bot. 
Centralbl., 1893, Beih., p. 447. || Comptes Rendus, cxvii. (1893) pp. 314-6. 
