516 QUEENSLAND AGRICULTURAL JOURNAL. [1 Junn, 1898. 
Again, there are organisms that are met with in the tissues of plants in a 
condition referred by German writers under van Beneden’s term “ Mutualismus’’ 
that exert, as far as has been observed, no apparent influence upon either the 
vigour or development of their hosts, or if otherwise only after a comparatively 
long period has elapsed, although it has been suggested that the advantages 
of this “ Mutualismus” may be only distinctly manifested when the plant is in 
need of a large amount of nitrogenus matter—for instance, during the ripening 
of the fruit.* These may yet prove to be destroyers of the true parasitic 
organisms occurring in plants, and therefore competent to prevent the maladies 
that these originate in them ; and if so, seeing that plants previously free 
from their presence may be artificially infected by them, as shown by Janse 
and other investigators, they may be available for inoculation having for its 
end the prevention of disease. 
* J. M. Janse: ‘‘Les Endophytes Radicans de quelques Plantes Javanaises,” p. 201, 
Leyden, 1896. 
