20(3 THE NATUEAL HISTORY REVIEW. 



effect is attributed in the nortli, in causing the disappearance of rare 

 plants, has none at Montpellier, for there are no bogs to drain ; and 

 the vast lagoons and marshes which border the Mediterranean still 

 occupy at least as great an extent as they did some centuries back. 

 When waste lands are broken up they are rarely enclosed, and from 

 the broken, rocky nature of the country, scattered spaces are usually 

 left undisturbed, quite sufficient to perpetuate the previous wild 

 vegetation. If the conversion of the forest of Gramont, below the 

 town, or of the greater part of the rocky hill of Cette, with vine- 

 yards and olive-grounds, the disappearance of the few meadows of 

 Boutonnet, or the reduction of the once extensive woods of Pinits 

 lialepensisj around Montferrier, may have spoiled some of the best 

 herborising grounds of the botanists of the sixteenth or seventeenth 

 centuries ; on the other hand, a few miles further north, from Mont- 

 ferrier to beyond the Pic St. Loup, many a ruin of cottage or castle, 

 barn or enclosure, many an ancient track of the spade or plough in 

 what is now the open garrigue, or wild barren pasture of the coun- 

 try, show the extent of land, or at least the numerous patches, once 

 under cultivation, but now again left to the operations of Nature, 

 checked only by the ravages of the real enemies of scarce plants 

 — the flocks of sheep and goats that roam over them, and the 

 countless swarms of the insect tribe. 



Cultivation alone has, therefore, had but very little effect in 

 destroying established species, and still less the wanton efforts of 

 botanical collectors. Montpellier has indeed had her dealers or 

 even amateurs who, after having supplied themselves with what they 

 conceived a sufficient stock of specimens of some of the rarer 

 species, have used every exertion to destroy the remainder; but 

 they have not succeeded. Lavatera onaritima, Pastinaca Opopanax^ 

 Diplotaxis JivmiliSj etc., are still to be met with. Even the exertions 

 of gardeners to collect for planting all the roots they could find of 

 Pancratium maritimum, and some other Liliacese and OrchidesB, from 

 their very limited stations, have not yet effected their extirpation. 



Dr. Planchon finally alludes to another cause of destruction, in 

 a manner which shows how steadily, although gradually, thinking 

 naturalists on the Continent, in spite of opposition, are adopting one 

 of the important principles laid down by Lyell and Darwin, that of 

 gradual change through countless ages versus sudden catastrophes. 

 " This cause," he says, "is the action slow but sure of the thousand 

 oflen inappreciable modifications, by which nature gradually substi- 

 tutes new species for the preexisting ones. This succession of vegetable 



