476 SUMMABY OF CURRENT RESEARCHES RELATING TO 



In the Gymnosperms the three-sided apical cell is sometimes replaced 

 by a four-sided one, sometimes by several. In the case of Araucaria 

 excelsa ditferent shoots from the same individual gave different results. 

 Notwithstanding the contrary assertion of Dingier, the researches 

 of Pringsheim, Hanstein, Strasburger, and Pfeffer on Salvinia, Azolla, 

 Marsilea, and Selaginella, show that there is no necessary connection 

 between phyllotaxis and the septation of the segments. The author 

 was unable to confirm the observations of Eeess on Equisetum scirpoides, 

 that there was any definite connection between the formation of whorls 

 and the segmentation of the apical cell. In Ferns with a three-sided 

 apical cell the leaf-spiral is sometimes homodromous, sometimes anti- 

 dromous to the spiral of the segments : in Struthiopteris the apical 

 cell is two-edged, but the phyllotaxis spiral. In Mosses the relationship 

 is simple because only one leaf proceeds from each segment. 



Influence of Light on the Formative Processes in Plants.* — For 

 the purpose of experiments on this subject. Dr. E. Wollny, employed 

 cubical zinc vessels filled with moist quartz-sand. One of these was 

 completely darkened by being covered up by another similar vessel. 

 The loss of water was replaced every day. The plants employed, 

 maize, peas, and beans, were observed for 35 days after appearing 

 above the soil. 



The conclusion arrived at was, that with decrease of the intensity 

 of the light the growth in length of the stem (in dicotyledons), or of 

 the leaves (in certain monocotyledons), was promoted, while, on the 

 other hand, the development of the assimilating and of the nutritive 

 organs and those for the absorption of water, was affected injuriously. 

 The amounts of carbohydrates and of organic nitrogenous substances 

 in the plant were in proportion to the intensity of the light, while the 

 amount of water contained in the plant was in inverse proportion to 

 the intensity of the light. 



Growth of Shoots of Potato when the roots are removed-t — Herr 

 C. Kraus describes experiments on the effects of the removal of the 

 roots from potato-tubers in relation to the retarding influence of 

 light on the shoots. No very definite results are arrived at. 



Sensitive Movements of Plants. | — The late Prof. E. Morren gives 

 a resume of the present state of our knowledge respecting the various 

 kinds of movements in plants, and contends in favour of his view 

 previously published of the essential identity of the process of digestion 

 in plants and in animals. 



Effect of different parts of the Solar Spectrum on Transpiration.§ 

 — Rev. G. Henslow gives a resume of results obtained by various 

 observers on this point, and discusses the various methods employed, 

 pointing out in particular the uncertainty of experiments on detached 

 parts of plants. He describes then a series of experiments of his own 



* WoUny's Forsch. a. d. Geb. der Agriculturphysik, vii. (1885) pp. 351-75. 

 See Bot. Centralbl., xxv. (1886) p. 141. 



t Ber. Deutbch. Bot. Gesell., iii. (1886) pp. 388-90. 



X Bull. Acad. Roy. Sci. Belgique, x. (1885) pp. 851-900. 



§ Journ. Linn. Soc. Lond. (Bot.), xxil. (1885) pp. 81-98. 



