SCIENTIFIC SUMMARY. 
71 
Perihelion passage, 1880, November 8*32198 
Longitude of perihelion . . 42° T 4" 
Longitude of ascending node 295 36 54 
Inclination of orbit . . 7 22 5 
Perihelion distance . . 1*1019 
There can be little doubt, therefore, about the identity of the two 
comets, so that it would give the comet a period of a little less than eleven 
years. This would give — 
Eccentricity of orbit . . . = 0*7767 
Semi-axis major . . . . = 4*9352 
The orbit of the comet would approach, therefore, very close to the orbit 
of the planet Mars, and, what is of still more importance, within 0*5 of the 
Earth’s mean distance of the orbit of the planet Jupiter , and not very far 
from the orbit of Saturn. Erom its mean approach to the orbit of Jupiter, 
and from the near commensurability between their periods of revolution, 
this great planet will produce very considerable perturbation in the motion 
of the comet. 
Faye’s Comet . — Since its discovery by Mr. A. A. Common, with his 
37-inch reflector, at Ealing, this comet has been observed by Prof. Temple 
at Arcetri, by Dr. Duner at Lund, Dr. Pechiile at Copenhagen, and Herr 
Yon Konkoly at O’Gyalla. The observed place corresponds very closely to 
the Ephemeris, and so affords a striking confirmation of the accuracy of 
the researches of Prof. Axel Moller. It is a very faint object, and scarcely 
within the reach of telescopes of ordinary aperture. 
BOTANY. 
Growth of Plants . — On December 16, Mr. Francis Darwin read, before 
the Linnean Society, two important papers, one on ‘ The power possessed by 
leaves of placing themselves at right angles to incident light,’ the other en- 
titled 1 The theory of the growth of cuttings, illustrated by observations on 
the Bramble, Rubus fruticosus ; ’ two papers which, though relating to 
different questions in the physiology of plants, have nevertheless much in 
common. Both of them bear on the relationship between the external 
and internal conditions of life ; between external forces, such as light and 
gravitation, and the constitution of the organisms on which these forces 
act ; and both tend to show the importance of recognizing in plants those 
specific forms of sensitiveness which may be said to determine the results 
which will follow external changes. We have to thank Mr. Francis Darwin 
and the authorities of the Linnean Society for the following abstract of these 
papers : — 
I. The behaviour of leaves in relation to light may be illustrated by 
the cotyledons of a seedling radish; if it is illuminated from above, the coty- 
ledons are extended horizontally, and are thus at right angles to the direc- 
tion of incident light. If the seedling is then placed at a window, so that it 
is lighted obliquely from above, and if the stem (hypocotyl) is prevented 
