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FERTILIZATION OF CEPHALANTHP^RA. 





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entirely dependent on insects for polli- 



nation is proved by the t'act that if the flowers are not so visited no secd- 

 <3apsules are protluc^d ; one often sees fruiting spikes of both species in wliicli 



only a flower here and there has f^et a capsnU\ 



iif 



in this manner, but this does not seem to happen very often, for it is rare to 



find flowers from wliich the poUinia have been removed. It is, however, 

 reguhirly self-fertilized, for praetieally every flower produces a capsule — a 

 sure sign tliat pollination is automatic and quite independent of any outside 

 noencv. How lias tliis come about in a plant whose conspicuous flowers arc 

 evidently adapted to attract insects? It is still quite capable of cross- 

 pollination^ and this f)robably occurs on the whole much more frequently 

 than the examination of a limited number of spo-imens out of the thousands 

 which exist might lead us to suppose. But it is a shade-loving plantj rarely 

 seen except under the shelter of trees, and often gro^ving in deep sliadow. 

 In the woods, however, the number of insects of suitable size is much nnu'c 

 restricted than in the open. There was thus a danger of there not being 

 enough insects lo secure adequate cross-pollination. It haSj therefore, 

 acquired the power of selt-fertili/.atlonj but it^ should be carefully noted that 

 this is in addition to, not in rtq)lacement of, the capability of cross-pollination. 

 It is a parallel case with that of Opltrys apifera, which has sup[dementcd its 

 original faculty of cross-pollination by aJding to it that of self-fertilization. 

 In both cases cross-pollination a])pears to be frequent enough to keep the 

 mechanism for that purpose in effieient working order, whilst sedf-fertilization 

 enables the plants to keep up their numerical stan^lard in years when insects 



are scarce. 



Thei 



'e IS n 



decadence or dt^generatitm in this. Instances occui 







cross-pollination fails to take place, and many insect-fertilized plants increase 

 their numbers by purely vegetative nutans, such as additional bulbs, creeping 

 rhizomes, etc. It would be absurd to interpret the provision of such 

 additional safeguards against unfavourable contingencies as a sign of 



decadence or degeneracy. 



If I am challetii''ed to produce |>roof tliat effective cross-jiollinatlon luis 



actually occurred in Cephalantliertt^ 1 



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difl 



Aiont Sa'eve near G-^neva (A. & G. Syn. iii. 877) and 



rnhiyuiosa^ found in Austria, which flowered 



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These hybrids 



could not possibly have occurred in a state of nature, except through eflectivo 

 visits by the same insect to both parents in each case. 



In the 'Journal of Botany/ 11)20, p. 71,1 protested against Dr. Wettslein's 

 proposal to abolish the genus Ce/Jialatdhera ami to includt^ it \u Epipaclis, Cr. 

 I then ado[)ted Darwin's view and sai i :— *' Ceplialantltera is a decadent 

 genus which has fallen from its high estate, assuming that it is really the 



