Notice on Vegetable Fossils. 269 
ment of translation has taken place since the precipitation, 
and even since the consolidation of the upper layer of psam- 
mite ; this movement, itis true, was not extensive, poe 
sufficient to break, in several points, the continuity of t 
stalks or trunks, so that their upper parts are, as it ara 
pushed aside, and do not correspond with the lower ones. 
It does not enter into my plan to describe these plants, 
nor to endeavour to determine to what family they may be- 
long: this is a very important and a very difficult subject, 
and one which cannot be treated cursorily. My son, aided 
by the counsels of Mr. Decandolle and the assistance ‘of the 
geologists, commenced, a long time ago, a separate work 
on that branch of Botany, which has for its object the study 
of fossil vegetables: for in giving names to this species of 
vegetables, too rapidly and too superficially, there would be 
danger of propagating, relative totheir genus, opinions which 
might prove to be erroneous. But, although I here speak 
only of the position of the stalks, and not of their ri I 
cannot refrain fron offering, on this last head, a few observa- 
tions which relate immediately to those of St. Etienne, 
which I have just described. 
At the mine of Treuil there are two distinct sorts of stalks, 
the one cylindrical, articulated, and striated, parallel to their 
edges ; these do not offer, in their interior, the least sign of 
brganized texture, their cavity, probably fistular, is entirely 
filled with a rocky substance of the same nature as those 
which compose the layers they traverse. These stalks are 
the most numerous, and differ much from each other in di- 
ameter, from only 2 to 3 centimeters (3 to 14 inches) to} 
or 2 decimeters (almost 4 to 8 inches) and perhaps more. 
_ Their greatest length appears to be 3 to 4 metres (10 to 13 
-) Their surface is often covered with a ferruginous, 
and even a carbonaceous crust or deposit. 
‘he other vegetables, less common, are composed o of 
hollow cylindrical stalks, which diverge towards their lower 
ex somes and seem to be wk ig in the manner of roots, 
with “5 trees of the family of the Palm tree. This result, 
which J sas announce, will be developed and preceded 
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