37^ Scientific Intelligence. 
28. Iron found in Bogota, in Humbddt lately 
communicated to the French Academy of Sciences an extract of 
a letter from M. Boussingault, at Santa Fe de Bogota, in which 
that traveller states, that he found in the Cordillera of Santa 
Rosa, between Timja and Bogota, many masses of very ductile 
native iron, one of which weighed about 80 quintals. 
BOTANY. 
26. Memoir on the Structure qf the Monocotyledones. — The 
author of this memoir, T. Lestiboudois, Professor of Botany at 
Lille, is already well known by a Dissertation, which he pub- 
lished in 1819, on the family of Cyperaceae, and in which he 
has not only traced the characters of all the genera belonging to 
this class hitherto known, but has proposed the establishment of 
several new genera. The memoir which we at present announce, 
relates to the anatomical structure of the stem of the Monocoty- 
ledones. It is well known that the stem of unilobous plants is 
not organised, and does not grow in the same manner as that of 
the dicotyledonous plants. In place of presenting, like these 
latter, a regular succession of ligneous strata, circularly arranged 
and enclosed the one within the other, around a central canal, 
destined to contain the medulla, the stem of a palm, or other 
arborescent monocotyledon, presents only a mass of cellular tis- 
sue, in the midst of which are scattered ligneous fibres in irre- 
gular bundles. It is by the formation of new layers, which are 
annually added to the outer surface of the ligneous body, and to 
the inner face of the cortical body, that the dicotyledones grow 
in thickness. In the monocotyledones, on the contrary, the 
growth takes place by the centre of the stem. In the former 
there exists two different systems, the one, central or ligneous, 
which grows externally ; the other, external or cortical, growing 
internally. There are therefore in these vegetables two sources 
of growth, while in the monocotyledones there exists but a single 
system, and a single focus of growth ; and as this one system 
grows internally, as has been proved by the beautiful observa- 
tions of M. Desfontaines, the author of the memoir thinks that 
it is the same as the cortical system of the monocotyledones. 
From whence is derived the conclusion, that the stem of palms, 
and of all other unilobous vegetables, is organised like the bark 
of the bilobous trees. On this account, he says, the dicotyle- 
