46 DR. HERBERT ON THE LOCAL HABITATIOX OF PLANTS. 



ously swamp plants ; the former of which flowered most pro- 

 fusely when aljsolutely in the water of a ditch. I afterwards 

 observed Gentiana verna, not less healthy, with Pinguicula vul- 

 garis, in sucti a hill-side bog near Thun as a jack-snipe is apt 

 to select for his residence. , 



Orchis (or Ilerminiuni) Monorchis is found in England on 

 slopes of chalk and stonebrash. I met with it in the reed-beds 

 close to the edge of the lake of Brienz, in company with Epi- 

 pactis (or Serapias) palustris ; and I also saw one vigorous plant 

 of Orchis militaris, which is reputed to grow only on dry chalk, 

 in the same marsh ; and tiiree in a flat, half-flooded meadow near 

 the sea, a few miles from Trieste. 



These observations lead me on to a question whicli has often 

 suggested itself to me, " Why do plants, which are found only 

 in particular situations, improve under cultivation, and (as I 

 believe to be the case) more so than those which are generally 

 dispersed?" and, consequently, "Is the soil or subsoil, on 

 which alone certain plants are found in a wild state, necessary 

 to them, or at least always best for them?" I think the 

 answers must be " No " to the latter question ; and to the 

 former question, " Because tlieir most dangerous rivals, which in 

 a wild state would overpower them, in richer soil are removed ;" 

 and that in truth the weaker plants in many cases are peculiar to 

 those soils which are not best for them, but where they can exist, 

 and where the gra.ss and other enemies cannot grow ^vith sufii- 

 cient strength to choke them. 



I found Crocus variegatus on the Carso of the mountains 

 behind Trieste, where the grass is so meagre that the grey stones 

 look through it ; but there a very small proportion of the bulbs 

 bear flowers, and still fewer yield seed. The crocuses of the 

 Ionian Islands are in the same manner dispersed amongst the 

 rocks and stones of the mountains, where there is scarcely 

 any grass, and in the spots where the cistus and other mountain- 

 shrubs do not overpower them ; but they flower and fruit very 

 sparingly, and the bulbs are very small and weak : and the 

 same I understand to be the case on the Alps of Trebizond, 

 where, as well as on Bithynian Olynqjus, the bulbs are curiously 

 diminutive from the poverty of the soil and bleakness of the 

 position. On Mount Roudi, in Cephalonia, the greater part of 

 those I saw were perishing from a nuirrain which seemed to 

 have been induced by very wet weather in February and March. 

 Yet crocuses brought from calcareous mountains into the gar- 

 den of a Dutch florist, and severed from their native soil, acquire 

 tenfold vigour and size of bulb. Few, however, of the cro- 

 cuses from rocky mountains flower when taken up till they 

 have been one year in cultivation. I apprehend the fact 



