SCIENTIFIC SUMMARY. 
519 
tion of Arthrolobium ebracteatum ,a native of the Channel isles and of France. 
If the law of migration from specific centres be granted, the plants of 
French type must have spread into these islands and the mainland from 
the south or south-east, and in both cases the spreading must have taken 
place during the existence of a vast continent, now partly occupied by the 
sea, which flowed in as a barrier before the Arthrolobium spread further 
than the Scilly isles. — Vide Journal of Botany, April, 1864. 
Action of Light on Blunts. — The veteran chemical botanist, Boussingault, 
has been inquiring into the difference between the chemical products arising 
from plants exposed to light and darkness. He finds that plants when 
germinating, — in other words, when living under ground, — tend to develope 
carbonic acid by allowing their carbon to combine with oxygen, and give 
rise to water by allowing the latter element to unite with their hydrogen. 
Hence, while in this condition they are rapidly losing weight. When, 
however, the young leaves appear above the surface and the plant is ex- 
posed to light, the weight increases, the carbonic acid of the atmosphere is 
decomposed, its carbon being retained. These normal results may be 
artificially produced in the case of mature plants, by exposing them to 
the influences of light and darkness. When submitted to light they in- 
crease in weight ; but when in darkness they gradually lose their bulk, 
and decompose. — Vide Comptes Rendus, May 16, 1864. 
Identity of the Vine-fungus and that producing Epidemics. — That the 
fungi which produce such distinct results as grape failure and diphtheria 
are one and the same species is certainly startling. MM. Vitray and 
Desmartis are of opinion that there is no distinction between the two 
species — O'idium albicans and O. Tuclceri. This conclusion has been formed 
from the circumstance that there is a sort of connection between the ap- 
pearance of the vine disease and that of various forms of epidemic laryn- 
geal maladies. The spread of the first has been followed by that of the 
second. It might, of course, be objected that botanists do not regard the 
two forms as belonging to the same species ; but then they are of the 
same family and genus, and there is no reason to suppose that pro- 
teism does not occur here as in other instances. — See a Memoire read before 
the French Academy, May 9, 1864. 
A New Substitute for Coffee has been proposed by M. Prevet, who sug- 
gests the employment of the seeds of the carob-tree instead of the fruit we 
use at present. It possesses a very agreeable flavour even without being 
sweetened with sugar ; and, apart from an economical view, it might be 
taken with benefit by those who find coffee too stimulating. 
Persistence of the Fertilizing Power of Pollen Grains. — M. Belhomme 
has published his investigations upon this subject. He has discovered that 
the pollen of monocotyledons preserves its properties for a much longer 
period of time than that of the dicotyledons. He experimented upon the 
following natural orders : Leguminosce , Rosacece, Myrtaceoe , Umbelliferce , 
Cactece , Crucifer ce, Malvaceae, Solanaceae, and Boraginacece of the latter 
group, and he found the pollen as fertile at the end of three years as it 
was at first. His experiments on monocotyledons were made upon the 
Liliacem and Amarylidaceoe, the pollen grains of which retained their 
fertility for a period of six years. Fertile and barren pollen may be 
