EXTRACTS FROM FOREIGN PERIODICALS. 
487 
while those of the second ring are only represented by a tuft of down, and those 
of the first ring have entirely disappeared.— >Annales des Sciences Naturelles. 
BOTANY. 
2. Phanerogamous Plants naturalised near Montpellier. By M.. 
Alphonse De Candolle. —Nothing, says M. De Candolle, is more difficult 
than to prove the introduction of a phanerogamous plant into the European 
floras. Our countries have long been in communication with the whole world, 
so that the species which might easily have been introduced have been introduced 
many centuries before accurate botanists could prove it. If new relations intro¬ 
duce, accidentally or voluntarily, new species, the frequent changes of our ex- 
extratropical climates, aud the extent of our culture (of plants), commonly pre¬ 
vents their being naturalised in a lasting manner. How many seeds escape 
from our gardens, which, nevertheless, cause no addition to the flora of our fields ! 
How many species have been sown without the boundaries of our cultivated 
grounds, from which nothing has resulted, or the produce of which has disap¬ 
peared after having struggled one or two years with the climate, and with indi¬ 
genous plants, exclusive masters of the land. 
Gouan of Montpellier, Grosse of Geneva, and several Parisian botanists, have, 
during many years, thrown handfuls of foreign seeds into our woods, meadows, 
and mountains, and, to my knowledge, no one of these is naturalised. 
The following, however, is an instance of successful naturalisation in the neigh¬ 
bourhood of Montpellier. Jussicea grandijlora^ an aquatic plant of the order 
Onagracece^ a native of Georgia and Carolina, was thrown into the little river 
Lez, six or seven years ago, by M. Delile, director of the garden of Mont¬ 
pellier. It has propagated and naturalised itself in an extent of many leagues, 
almost so as to obstruct the mill-streams. This year (1836), in September, I 
have seen it erecting its beautiful yellow flowers in the midst of the Polygonum, 
Mentha, &c., which have always covered the peaceful waters of the banks of the 
Lez. It occurs abundantly above the Pont Juvenal; and if we then repair to 
the neighbouring inclosures destined for the cleaning of wool*, we can compare a 
complete and permanent naturalisation with the ephemeral introductions which 
botanists have frequently mentioned. The fact relative to the Jussicea admits of 
no doubt. The cause of its success appears to me to be the nature of the station 
of J. grandiflora. The plants which live more or less submerged in water are 
commonly found in countries distant from each other. They are, so to speak, more 
sporadic than the generality of species belonging to the same genera or families. 
They accommodate themselves more easily to all climates, because the medium 
* The wools of the East, dried at the Pont Juvenal introduce annually some species, but 
they are not found to spread and multiply in the country. 
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