THE AXCIEXT AXD MODERN TLOEAS OF MONTPELLTER. 217 



noticed and uninjured for very long periods. The Lobelia produces 

 a large (Quantity of t?eed, and on the Continent will vary much in 

 number of individuals in difterent years. Most probably the seed 

 does not always find meteorological or other conditions favourable 

 for germination at the time it is shed, and is often destroyed or 

 loses its powers of germination before these conditions occur. 



If human agency has been much more active in Britain than 

 at Montpellier in the destruction of spontaneous vegetation, it has 

 been infinitely more so in the facilities aftbrded to the introduction 

 of new ones, as well by direct importation and cultivation as by our 

 extended commerce with all parts of the world, our importations of 

 foreign grain and other agricultural seeds, of foreign wools, timber, 

 and other goods, by our heaps of ballast from various countries ; in- 

 dependently of the ocean currents, w^nds, bird-flights, &c., which, 

 much more than at Montpellier, may, without the aid of man, keep 

 up a seed communication not only with the opposite Continent, but 

 even w4th more distant lands. The result is accordingly in some re- 

 spects greater than at Montpellier, but not in proportion to the 

 greater means ; partly in consequence of our climate imposing nar- 

 rower limits on the sources wdience plants can be successfidly im- 

 ported. 



The subject of species introduced into Great Britain has been 

 largely treated of by A. De Candolle in his Gtographie Botanique, 

 and by Hewett AV^iitson in the fourth volume of his Cybele. AVe 

 learn from the latter : " It appears that the Flora of Britain must 

 now include upwards of three hundred species (320 to 330 by the 

 lists before printed), which are believed or conjectured to have 

 been introduced to this island by the agency of mankind, either 

 intentionally or accidentally. The foreign ingredient thus consti- 

 tutes nearly one-fifth of the Elora, reckoned by species, after striking 

 out of the long list several of the least suspected, and of the least 

 established species." 



On looking through the long list w^e find that, with the exception 

 of nine or ten North American species, the wdiole are European 

 plants, Avhich even if now occasionally reintroduced, may be and 

 probably are,, with few exceptions, the same as those introduced and 

 established long before the sixteenth century. The cultivation of 

 simples, medicinal and officinal plants, was much more prevalent in the 

 middle ages than in the present day, and has left its traces in many 

 a " denizen" lingering around the ruins of castles and monasteries 



N.H.R.— 1865. Q 



