MALADIE ET SYMBIOSE 271 



and although the cluster eventually was to arise within the orchid, 

 yet even there its existence must be dependent upon some kind 

 of interior " region de passage," on osmotic processes, etc. We 

 are told that 



on peut supposer que ces regions eminemment permeables sont capables 

 d'excreter des substances solubles attractives pour les champignons qu'on 

 sait sensibles a des actions chimiotropiques. 



This view of the matter rather contradicts the idea of a one- 

 sided " Selection " of the orchids by the fungi ; and it suggests 

 instead the development of considerable symbiotic awareness of, 

 and preparedness for, each other's needs on the part of the two 

 organisms, a very different thing from Selection. Neither is it 

 suggestive of " Selection " by the fungi when we are told that : 



Si des embryons d'Odonioglossum se trouvaient sur un milieu ou co- 

 existent les divers champignons que je leurs offrais isolement, ils pourraient 

 faire un choix entre eux et se laisser penetrer seulement par les plus actifs. 

 Cette faculte d'exercer un choix entre divers champignons, peut event- 

 uellement limiter les risques auxquels les embryons d'Orchidees doivent 

 etre communement exposes quand ils rencontrent a la fois des champignons 

 utiles ou nuisibles pour leur developpement. 



So far then from there being a " Selection " by the fungi, 

 we have here rather a case resembling that of many flowers which 

 permit access only to those nectar seeking insects which render 

 adequate counter-services to the plant. In both cases the 

 discriminating agent is the higher plant ; and in both cases, the 

 sanction of Nature depends upon the bio-economic usefulness 

 of the union. The " risks " run by the orchids, alluded to by 

 Prof. Bernard, do not, strictly speaking, begin with the meeting 

 of a particular fungus ; they began with the habit of in-feeding 

 which provided the " soil " for infection, inasmuch as the habit 

 universally makes for " surpluses " of an undesirable kind 

 the surpluses of dishonest labour. 



Without a court of appeal, such as is constituted by 

 Bio-Economics, we shall for ever continue muddling with 

 " Selections " and " Adaptations," without ever arriving on firm 

 ground. 



Failing Bio-Economics, the French Botanist feels again 

 obliged to plunge into Pathology ; and, under the head of 

 " Infestation Primaire, Vaccination," he ventures upon certain 

 interpretations, which are for the most part, I believe, based 



