80 
POPULAR SCIENCE REVIEW. 
Effects of Sunlight on Vegetation. — Experiments in reference to tlie effects 
of sunlight of different intensities in developing the chlorophyll in plants 
have been recently made by M. Prillieux, and have been reported by him 
to the French Academy of Sciences. Galignani gives the following abstract 
of the paper : — In former experiments sunlight was weakened by being re- 
ceived through water or glass shades, and the results were therefore liable 
to be modified by the absorption of rays. To avoid this, M. Prillieux, by 
means of a heliostat, caused a cone of light six metres in length to fall into 
a dark room, and he then placed a series of five pots, each containing barley 
that had been reared in the dark, within the luminous region. No. 1 was 
placed at a decimetre’s distance from the focus of the lens through which 
the solar rays were transmitted ; No. 2 was placed at 16 times that distance; 
No. 3 was separated from the latter by a further interval of 12 decimetres ; 
No. 4 was at 55 centimetres from this; and No. 5 stood at 57 decimetres 
from the focus. The experiment lasted from half-past one to half-past four 
p.m. ; and at the end of these three hours it was found that all these little 
plants, except those of No. 1, had become green to very nearly the same 
extent ; while those that had remained nearest the focus, and had therefore 
been exposed to the fullest sunlight, had remained as yellow and sickly as 
before. 
The Affinities of the Hydroleacece. — According to Mr. A. W. Bennett — 
who has communicated a paper on the subject to the Linnsean Society 
(November) — the Hydroleacece , which have been severally referred to the 
Convolvulacece and Hydrophyllacece , must be retained as a separate order, 
including, however, two tribes, the Ilydrolece with septicidal, the Namece 
with loculicidal dehiscence. The tendency which exists in several species 
of Hydrolea to substitute for the normal bilocular a trilocular ovary, indi- 
cates, in the author’s opinion, a closer affinity with the Polemoniacece than 
has been generally supposed. From Solanacece they differ by their two 
styles and straight embryo ; from Scrophulariacece , by their regular corolla, 
five equal stamens, and two styles. The order is essentially tropical and 
sub-tropical, and especially American. The genus Hydrolea , which is 
nearly synonymous with the sub-order Hydrolece, ranges from Arkansas to 
Monte Video, with a few Asiatic and African species, to which Mr. Bennett 
adds two new ones, fiom Tropical Africa, contained in the Kew Herbarium. 
A Fungus Parasitic on the Coffee Plant . — A curious fungus, which has 
lately sprung up in Ceylon in the coffee grounds, has been examined by the 
Rev. M. J. Berkeley, F.It.S., who has sent a letter on the subject to the 
Gardiner's Chronicle. It is allied to the Mucors , but is erected into a new 
genus by Mr. Berkeley. 
The Neio Medal of the Royal Horticultural Society. — The Council of the 
Royal Horticultural Society has resolved on issuing a bronze medal, to be 
called the “ Rare Plant Medal,” and to be awarded at any of the society’s 
meetings, for the first exhibition in this country of plants of great botanical 
interest. 
Filling up Von Martins' Place at the French Academy. — At the meeting 
of the Academic des Sciences, on Nov. 22, this election took place, and several 
candidates presented their names. The Secret Committee, which generally 
practically decides these matters, gave the following as the result of its 
