DR. HERBERT ON THE LOCAL HABITATION OF PLANTS. 47 



to be this — that, if the seed of the crocus were to fall in 

 such a goodly heritage without the protection of the weed- 

 ing-hoe, it would be strangled in its birth by stronger oc- 

 cupants ; and that, on the chalk and other calcareous rocks, 

 there are places where few vegetables can exist ; while the 

 bulbs of this and some other genera take refuge there and 

 get a poor livelihood in peace and quiet. I saw a Crocus, 

 a Sternebergia, and an Ornithogaluni growing in contact with 

 each other aloft on the meagre sod of Mount Qinos ; but not 

 a seed-pod of the Sternebergia could be discovered, and very 

 few of the crocus. In a more fertile sod they would have been 

 choked by some stronger plant, but they would rejoice in a 

 better soil, if protected against the oppressor. 



The usual habitation of the various species of crocus is on calca- 

 reous mountains ; and, as such are of various descriptions, they seek 

 a more elevated or a steep position, which is unfavouiable to the 

 growth of grass, on those whicli are most fertile. .Some species, 

 however, like more humidity than others ; and C. speciosus and 

 Byzantinus, which desire a fertile soil, seek the shade of woods, 

 where the roots of trees perforate the earth and render it looser 

 and drier than it would be otherwise. From the mountains be- 

 hind Trieste to the south of Greece the soil oti which crocus 

 grows becomes gradually redder as we advance, and is intensely 

 so in the neighbourhood of Nauplia : in Negropont it is browner, 

 and on the lofty Veluchi, in .^tolia, slightly ferruginous towards 

 the summit ; but the bulbs are more vigorous in detritus of 

 greyish greenstone, on its lower projections and near its base. 

 In all these positions the soil is rather strong, but dry. One 

 only species in the Cyclades is said to grow in sand upon clay. 



The compost, in which the Dutch raise their improved bulbs of 

 various kinds, is known to be (see Sismondi, des Jacinthes) a 

 compost of humus, obtained from thoroughly decayed elm-leaves 

 and dung of stall-fed cattle, and mixed with sand deposited by 

 the sea on a bed of prostrate timber of unknown antiquity, in 

 which there is probably nothing calcareous. Does it not then 

 appear that the case stands thus — not that calcareous matter is 

 essential to the growth of crocus, or even a useful auxiliary, 

 but that crocus can bear the sterility of elevated calcareous 

 mountains better than most other plants of stronger growth ? If 

 that be true of one genus, it will probably be applicable to 

 others. 



Let us proceed from that consideration to more general 

 views. The richest soils, if well moistened, will necessarily be 

 occupied by the vegetables which grow most rapidly, and with 

 such spreading and persistent foliage as to prevent slower but 

 more robust rivals from gradually supplanting them ; but that 



