352 SUMMARY OF CURRENT RESEARCHES RELATING TO 



folium and periclymenum are nocturnal flowers pollinated by hawk- 

 moths ; L. sempervirens is pollinated by humming-birds. 



Dr. W. Taliew * describes the mechanism of pollination in Borrago 

 officinalis. It is visited by hive-bees and humble-bees, which use the 

 tooth-like appendages of the stamens as holdfasts to grasp with their 

 legs, as well as the scales (staminodes) which form a whorl external to 

 the stamens. The sucking out of the honey shakes out the pollen on 

 to the abdomen of the insect. Similar contrivances are found in other 

 Borraginese — Cerinthe, Symphytum, &c. 



From a series of observations made by MM. S. Korshinsky and 

 N. Monteverde f on the pollination of the buckwheat, Polygonum Fago- 

 pyrum, they conclude, from its pronounced heterostyly and the occurrence 

 of nectaries, that it is almost entirely dependent on the visits of insects 

 for the production of fertile seeds ; artificial self-pollination hardly 

 ever resulted in complete fertilisation. 



(S) Nutrition and Growth (including' Germination, 

 and Movements of Fluids). 



Assimilation of Free Atmospheric Nitrogen by the Aerial Parts 

 of Plants.^ — Dr. L. Hiltner brings forward evidence to show that the 

 power of assimilating the free nitrogen of the atmosphere is by no 

 means confined to the bacteroids which inhabit the root-tubercles of the 

 LeguminosEe and other plants, but is possessed also by endotropic myco- 

 rhiza in the underground or aerial parts of plants. This has been 

 shown to be the case by the author in the case of the mycorhiza of 

 Podocavpus ; and he believes it to be so also with the mycorhiza of 

 other Coniferse, as well as that of the Ericaceae and Orchideas. He 

 now gives experimental reasons for the belief that the fungus found 

 by Nestler and others § in the ovary of Lilium temulentum has also the 

 property of increasing, by absorption from the atmosphere, the small 

 amount of nitrogen contained in the host-plant. 



Absorption of Potassium by Plants. || — M. Th. Schloesing, jun., 

 has determined that plants can utilise the potassium salts in the soil 

 when present even in the proportion of only a few millionths. The 

 alkali is taken up in the form of potassium phosphate. 



Variation produced by Grafting.lf — Continuing his observations of 

 the effect of grafting on Phaseolus vxtlgaris, M. L. Daniel states that 

 the effect of grafting one race on another is manifested in three different 

 ways : — the tendency to a dwarf habit is increased ; a combination 

 results, more or less complete, of the characters of the two races ; and 

 a tendency is brought about towards the production of new varieties. 

 This tendency is greater if the plant grafted is a cultivated than if it 

 is a wild variety. 



' Culture of the Lupin.** — From prolonged culture of two species of 

 lupin, Lupinus albus and angustifolim, MM. P. P. Deherain and E. De- 



* Bot. Centralbl., lxxxi. (1900) pp. 1-3. f Tom. cit., pp. 167-72. 



t Centralbl. Bakt. u. Par., 2" Abt., v. (1899) pp. 831-7. 

 § Cf. this Journal, 1899, p. 191. 



|| Comptes Kendus, cxxx. (1900) pp. 422-4. f Tom. cit., pp. 665-7. 



** Tom. cit., pp. 20-4, 465-9. 



