LANDMARKS OF BOTANICAL HISTORY — GREENE I39 



the English ivy. This, as they well understood, is most commonly 

 seen as a trailing or climbing shrub, the stems rooting everywhere, 

 all the foliage leathery, of angular outline and dark green. In this 

 phase the plant may pass the whole of its existence and remain 

 fiowerless. Occasionally, when very old and having climbed by 

 wall or tree trunk to sunlight and upper air, a new thing happens. 

 Out of the summit of this dark-green creeping ivy mass an upright 

 bush appears; its branches not rooting, firm, independent, bearing 

 leaves not leathery in texture, not in the least degree angled, and 

 even of a decidedly light green ; and this bush up at the top of the 

 ivy will in course of time bear flowers and fruits. The ancients 

 before Theophrastus had no difficulty in explaining this phe- 

 nomenon. Their firm belief in all sorts of transmutations as taking 

 place in nature saved them any perplexity. They held these two 

 phases of the ivy to be generically distinct, and had their fully 

 established names for the two genera: Helix for the rooting and 

 climbing plant of dark angular foliage, Cissus for the upright bush 

 of the pale thin ovate leaves, that into which the Helix sometimes 

 in old age transformed itself. 



Again Theophrastus fails to be satisfied with the popular 

 philosophy, and suggests one that he thinks more rational. If 

 every plant of Helix under the right conditions and with fair 

 opportunity would develop a Cissus bush at summit in maturity 

 or old age, which he says some agree to as being probable, then 

 he would be of the opinion that the distinction between the two 

 is not a generic one, but only a matter of the age of the individual.^ 

 He who has taken note of this philosopher's way of advancing his 

 most revolutionary propositions with urbane reserve will under- 

 stand him as here pronouncing against the time-honored doctrine 

 of a generic change from Helix to Cissus, and as averring that these 

 are but the young and the old phases of one species. It was the 

 inductive philosopher, the scientific botanist, undermining as it 

 were by stealth an ancient botanical superstition, because he had 

 a truly scientific proposition to put in place of it. In this instance 

 Theophrastus was, as usual, far in advance of his own time. For 

 centuries after him men still held to the bigeneric ivy. I should 

 confidently expect to find this pre-Theophrastan view surviving 

 still among the peasantry of some parts of Europe where Hedera 

 Helix is common and well known. 



Living in the midst of a time when a thousand superstitions 

 prevailed everywhere concerning plants, their origin, magic powers, 



» Hist., Book iii, ch. 18. 



