SCIENTIFIC SUMMARY. 
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Hybrid Plants returning to their Original Species. — M. Naudin, having 
fertilized plants of Datura stramonium with others of D. Tatula, afterwards 
sowed the seeds produced by this union, and obtained hybrids of the first 
generation. These hybrids were isolated ; and a few seeds coming to 
maturity, they were sown in April, 1862, and produced twenty-two plants 
of the second generation, viz., five of Datura stramonium in all its purity, 
whose fruits ripened and came to maturity ; and nine typical plants of 
Datura tatula. The remainder were more or less of a hybrid character. 
M. Naudin believes that this third generation of the hybrids will turn 
completely to D. tatula. These remarkable facts, which demonstrate the 
fact of the spontaneous disappearance of fertile hybrids, without the inter- 
vention of a crossing with one or other of the parent species, appear to 
M. Naudin at present inexplicable. 
Acclimatisation of Japanese Plants. — M. Simon, writing from Japan, con- 
tinues to recommend valuable plants for introduction into the Jardin 
d’ Acclimatisation. The hemp palm ( Chameerops excelsa ) bears a tempe- 
rature of 10° Fahrenheit, requiring no particular care. The stalk of each 
leaf is covered with filaments of various fineness, of which the coarsest are 
used for ropes, and the finer for nets. Another plant he speaks of is the 
soja, a kind of bean used by the Japanese for a condiment, and a very 
savoury adjunct to almost every Japanese dish. 
The Sago Palm. — Mr. Wallace, who has returned, laden with valuable 
information, from his Eastern travels, speaks of the sago palm as the staff 
of life to the inhabitants of New Guinea and the adjacent islands. He 
described it as a truly extraordinary sight to behold a whole tree trunk 
converted into human food, with as little labour as is required to convert 
corn into bread. A single good tree will produce six hundred pounds of 
sago cakes ; and with an expenditure of ten days’ labour, a man may pro- 
duce food sufficient for a year’s consumption. The natural result is 
improvidence, laziness, degradation, and misery. 
Botany of North Yorkshire. — Local floras and local faunas being of great 
value and importance, we gladly notice the preparation of a work to 
include the flora of this interesting part of England. North Yorkshire 
stands midway between the North and South of Britain, and can claim for 
its own about three in four British species. About 1,600 species of flower- 
ing plants, ferns, and mosses will be described ; and as a valuable adjunct, 
sets of the rare and critical plants of the district are prepared, containing 
each about one hundred specimens. 
The Cotton Substitute. — The substance proposed by Mr. Harben, and 
spoken of in our last as favourably mentioned as a substitute for cotton, 
has now long been known to be the fibre obtained from the Grass Wrack 
(Zostera marina'). The subject has since that time been before the public, 
and well canvassed by practical men. The result, at present, appears 
to be that, although it may prove useful as a supplement to cotton, or for 
mixing with other fabrics, neither the nature of the fibre, nor the source 
of its supply, renders it probable that it can make us independent of the 
cotton-plant. 
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