1816.j Royal Institute of France. 395 
chemical nature is more similar to that of the fungi than to the 
seeds of corn. Its smell, likewise, its taste, and its poisonous pro- 
perties, agree with its fungous nature. It is known that bread made 
from blighted wheat occasions serious diseases; among others, the 
dry gangrene, so well known in Sologne, is ascribed to it. M, 
Decandolle, aware of the importance of destroying so dangerous. a 
production, or at least of diminishing its propagation, conceives 
that this object would be attained by obliging the proprietors in 
countries subject to the disease to furnish annually a measure agreed 
upon which should be burnt upon the spot. 
This skilful botanist, who has already derived so much advantage 
from the study of the aberrations of ordinary forms to elucidate the 
theory of botany, has employed himself, under this point of view, 
with those brilliant monstrosities called doubie flowers. Their 
production is usually ascribed to the transformation of stamina into 
petals ; but M. Decandolle shows that the transformation or multi- 
plication of different other parts of the flower may equally contri- 
bute to it. The pistils, for example, change into petals in certain 
varieties of anemonies, The stamina themselves may be transformed 
either by their threads or their anther ; and it is thus that aquilegia 
furnishes florists with two sorts of double flowers quite different : 
and as these two ways of doubling take place only in flowers which 
have two kinds of petals in the natural state, the author draws from 
thence a new proof of his assertion that the petals of plants are not 
$pecious organs, but only a certain state of the stamina. He points 
out another kind of double flower, produced by the organs trans- 
forming themselves, not into plain petals, but into bundles of 
petals. This happens most frequently in the families in which the 
corolle in the natural state show marks of ‘doubling, as in the 
pinks. He next examines those flowers in which the alteration of 
the organs does not amount to a complete transformation, but 
greatly increases the bulk of certain coloured parts, as happens in 
hortensia and guelder rose (viburnum opalus). Applying to these 
different metamorphoses names analogous to those which M. Haiiy 
gives to the different varieties of crystals, he brings them, notwith- 
standing their apparent irregularity, under certain laws, and a 
precise nomenclature. 
M. de Beauvois, wishing to prevent the fatal accidents so often 
occasioned by the ignorance of the common people of the qualities 
of different fungi, has composed a manual for the use of those who 
are fond of Teer: fan in which he describes, in a language intel- 
ligible to every one, the species of this plant which may be eaten 
without danger, and points out the necessary precautions even with 
the most innocent of them to prevent them from occasioning any 
inconvenience ; but the most certain rule is only to eat mushrooms 
raised in beds, and not to eat too many of them. 
M. de Mirbel has published the Elements of Vegetable Physio~ 
logy and of Botany, in two volumes, with a volume of plates. All 
sthe important facts respecting the anatomy of plants, their func- 
2c2 
