148 



1400 M. above the level of the sea ^), whereas my fungus 

 was found on the Government Cinchona Plantation at a 

 height of 1600 M. According to the description there are 

 certain différences between this fungus and the one I 

 cultivated. So far I hâve had no opportunity to compare 

 the two fungi; in my opinion this would only be possible 

 by cultivating them, the two examples having been grown 

 under such différent circumstances. And how important a 

 part external conditions play in the growth, is a well 

 known fact to every mycologist who has cultivated fungi 

 on différent substrates. 



I very much regret to hâve no opportunity of making 

 pure cultures of the Armillaria toadstools that were grown 

 from my pure cultures of the white root Cinchona fungus 

 to infect the Cinchona thereby, as it would be interesting 

 to fînd out, whether this fungus is a true or wound parasite. 

 Neither is it possible for me to investigate whether ail 

 of the stérile white internai mycelia, parasitic to the 

 Cinchona, and which I called the white root fungus, will 

 develop Armillaria fruit bodies in any case, or whether 

 still other fungi form the peculiar mycelia I described above. 



In concluding this article I désire to extend my warmest 

 thanks to ail those who hâve lent me their valuable 

 assistance in making this investigation. 



Amsterdam, October 1917. 



^) P. Hennings, Fungi. Monsunia von O. Warburg; Band I. p. 20, 

 Leipzig. 1900. 



DESCRIPTION OF PLATE. 



Plate XIV. The Erlenmeyer flask containing pure cul- 

 tures of the white root-fungus and two toadstools photo- 

 graphed by Mr. Van der Gen, Cand. biol. Utrecht. 



