28^ M. Brongniarfs Ohservations on Some 



We leave to M. Dureau himself the task of presenting this 

 fact in his work, surrounded by all the considerations which at- 

 tach to it, and which will reduce it to the place which it ought 

 to occupy in science. But the fact itself, which at once con- 

 nects what is with what has been^ by making to disappear an 

 interval of two thousand years, and which refers to so early a 

 period the first recognitions of the laws of human life, appeared 

 to us so curious and so interesting, that we gladly availed our- 

 selves of M. Bureau's permission to attach it to our note, and 

 publish it. 



Observations on some Fossil Vegetables of the Coal Formation, 

 and on their relations to living Vegetables. By M. Ad. 



BnONGNlAllT. 



Jl. he study of fossil organic bodies is so much the more diffi- 

 cult, in proportion to the obscurity in which the structure of the 

 living beings which they resemble is still involved. Numerous 

 collections of comparative anatomy have become necessary for 

 the determination of the isolated bones that are found buried 

 in the strata of the globe. Without such collections, it would 

 have been impossible to fix the families to which those animals 

 of former times are to be referred, to determine their genera, 

 and to limit their species, with accuracy. With reference to fos- 

 sil botany, we are still entirely deficient in collections of this de- 

 scription. A few specimens brought home by travellers, often 

 without the precise species being satisfactorily determined, are 

 scarcely sufficient to afford an idea of the parts of vegetables 

 which cannot be preserved in herbaria. The deficiency of ob- 

 jects of comparison is so much the more detrimental to the pro- 

 gress of this part of natural history, that, as the fossil vegetables 

 of the old formations appear to be almost all referrible to the 

 great arborescent monocotyledonous vegetables, at present con- 

 fined to the warmest parts of the globe, the examination of the 

 plants which grow in our own country can throw but little light 

 upon the structure of the trees which composed those ancient 

 forests. If there be added to this the changes which compres- 

 sion, and the otheV phenomena which have accompanied 



