MALADIE ET SYMBIOSE 265 



whilst involving more balanced and generally more widely useful 

 work, also provides more reliable, more endurable and more 

 elevating stimuli than fungal Symbiosis. On Prof. Bernard's 

 view it would almost follow that Neottia, with its " continuous 

 Symbiosis," should come nearest amongst terrestrial orchids to 

 rivalling the status of the palm tree, which, of course, it is far 

 trom doing. Neither, in my opinion, could Vandopsis lisso- 

 chiloides, in the Philippines, achieve its feats of monopodial 

 growth if it lived Neottia-like in and upon the humus. There are 

 evidently different developments of monopodial growth, just as 

 there are different kinds of Symbiosis, though the difference be 

 unrecognised by present classifications. 



Prof. Bernard thinks that the replacement of sympodial by 

 monopodial modes of vegetation through the continuous develop- 

 ment of one and the same bud (instead of periodic development 

 of successive buds) is one of the most interesting episodes in the 

 history of the orchids. His belief that the event is due to the 

 progress of (fungal) Symbiosis and coincides with the change 

 from periodic to continuous Symbiosis, has led him to suggest 

 the still bolder hypothesis that : 



La tendance a la vegetation arborescente, que manifestent certaines 

 Sarcanthinees chez lesquelles ce mode de vegetation monopodial s'est 

 institue, est un fait des plus suggestifs, dont 1'existence me porte a croire 

 qu'on pourra un jour decouvrir un lien entre les progres de 1'evolution en 

 symbiose et I'apparition des plantes arborescentes. Mais assurement 

 1'etude des Orchidees no peut fournir que des documents imparfaits pour 

 la solution de ce probleme general, et ce que j'en deduis ici n'est qu'a titre 

 de suggestion. 



Whilst agreeing with the reservations, I would also agree with 

 the hypothesis itself, provided that by " Symbiosis " is meant 

 Norm-Symbiosis, which alone is capable of permanently providing 

 the wherewithal required to achieve effective arborescence. 



It is not a little curious at this stage of the disquisition to 

 find Prof. Bernard unwittingly paying a tribute to Norm-Symbiosis 

 as the great determinant of plant-evolution. For, in support of 

 his contention that the Ophreae the next group of orchids 

 examined by him are rather highly evolved, he stresses the fact 

 of adaptation to insect-fertilisation, which fact is manifested by 

 the conformation of the respective flowers. But, surely, it is 

 this class of^adaptation, with all it involves in progressive socio- 

 physiological evolution, that represents the Norm of Symbiosis 

 in the world of life. Compared with it Prof. Bernard's ' ' Symbio- 



