MALADIE ET SYMBIOSE 277 



for highly concentrated solutions, and to determine the compo- 

 sition of its protoplasm in a favourable sense by means other 

 than those suggested by him, e.g., by creating the conditions 

 auspicious to the incidence, and the increasing value of, cross- 

 fertilisation and at the same time to the distribution of seeds 

 by animal-agency. And the secret to the consummation is this : 

 service. To have failed in fundamental service is, in my opinion, 

 the root-defect of orchidean life.] 



From considerations to be drawn from Darwin's Fertilisation 

 of Orchids, we may now infer strong confirmation of the view that 

 orchidean Norm-Symbiosis is in decay, owing largely to the 

 distractions and exactions of Luxury-Symbiosis with fungi. It 

 is as though the propitiating of the fungi by the orchids involved 

 physiological expenditure too great to allow of adequate margins 

 for successful Symbiosis with superior helpers, namely, the 

 insects. 



Symbiosis, of course, was unknown when Darwin wrote ; 

 but having been blamed for propounding the doctrine that 

 the higher organic beings require an occasional cross with 

 another individual, without giving ample facts, he wished to 

 show in this volume that he had not spoken without having gone 

 into details. 



Direct proofs of his contention were given in his The Effects 

 of Cross and Self -Fertilisation in the Vegetable Kingdom (the cases 

 being for the most part, if not all, drawn from dicotyledonous 

 plants). Here, in the case of the (monocotyledonous) orchids, 

 Darwin confines himself in the main to pointing out the frequency 

 and perfection of the contrivance for cross-fertilisation, which 

 would seem to render it highly probable that cross-fertilisation 

 was the pristine condition of life amongst the ancestors of the 

 orchids ; and in view of these facts, Darwin thinks it again 

 demonstrated that there is something injurious in self -fertilisation, 

 and he concludes that " it is hardly an exaggeration to say that 

 Nature tells us, in the most emphatic manner, that she abhors 

 perpetual self-fertilisation." 



But, although the apparatus for cross-fertilisation persist, the 

 institution itself may have lost much of its former virtue. 

 The value of the respective biological interaction depends 

 largely upon the quality of the surplus products which the 

 plant has to offer. In the case of the orchids, Darwin himself 

 provides evidence to show that plants differ widely in the quality 



