THE A^X'IENT AND MODERN FLOEAS OF MONTPELLIEE. 207 



forms, in one and tlie same region, is a well-establislied law, and 

 without going back to geological periods, when it presents itself to 

 US on an immense scale, we can recognise its effects in the present 

 period." After alluding to the substitution of one tree for another 

 as the prevailing essence of forests, as observed in other countries, 

 and to the disappearance of trees and shrubs common in former 

 ages about Montpellier, as more especially considered in the memoir 

 we shall revert to further on, he further observes : — 



" But if the operations of Nature are carried on with a certainty 

 that our feeble means never obtain, it is also with the slowness of a 

 power that has ages at its disposal. iN^othing, therefore, is more 

 difficult to establish than this gradual progress of certain species 

 towards destruction during periods when the action of physical 

 causes can be leisurely exercised without being disturbed by human 

 intervention. 



•' To such a cause may, perhaps, be attributed the local disap- 

 pearance of trees formerly common in some of our woods : the 

 Nut tree and the Holly, much less frequent in the low grounds than 

 they used to be ; the Sycamore indicated by Magnol and Gouan 

 at the Capouladoux, but which, to our knowledge, has not been found 

 there in our days. These are, however, probabilities only; man 

 may have at^sisted nature and hastened the loss of these species in 

 restricted localities. At all events it will require much time yet 

 before the work of their destruction is completed over oiu' whole 

 region ; and before these species, scattered here and there in the 

 Cevennes, can be entered in the list of our extinct species." We 

 may suggest in addition, that these three trees, as well as the wild 

 gooseberry, alluded to by Planchon as disappearing also from the 

 low ground, all thrive best in a more temperate climate, and that the 

 additional exposui'e, occasioned by the destruction of woods, may 

 have been the last stroke that disabled them from resisting the 

 difficulties they had to contend with during the burning Montpellier 

 summer. 



As the general result of physical causes, combined with human 

 action, Dr. Planchon can only establish the loss from the region of 

 Montpellier of five species since the sixteenth century. Five 

 species, however, in three centiu-ies, might be considered as a large 

 number in proportion to what has been observed elsewhere, if all five 

 liad been really old well-established species. But two of them, 

 Zupinus luteus and L. varius, from the details he gives further on, 

 can scarcely have been more than weeds of cultivaLion, hikI should 



