56 Transactions British Mycological Society. 
study of numerous types of infection he holds that the fungus 
when in the root leads a life independent of the exterior and 
that it must therefore obtain all its nutriment from the plant. 
Comparing its mode of life with that of fungal parasites such as 
Peronosporaceae he decides against its parasitic nature and 
regards it as a special form of saprophyte—an internal sapro- 
phyte. 
Ternetz working with the fungi from Ericaceae records as a 
result of careful experiments that they are able to fix free 
nitrogen. From a theoretical point of view this is of extreme 
interest, fitting in well with what is known concerning the 
bacteria in the root nodules of the Leguminosae, but so many 
discordant results have been recorded in such studies that it 
would be well not to accept these without confirmation. Inci- 
dentally it may be again remarked that Burgeff was unable to 
show any such fixation in orchids. 
Owing to the totally different complexion that Bernard’s 
work put upon the mycorrhiza question, his views are of par- 
ticular interest. He regards the fungus in orchids as a parasite: 
an orchid suffers from a benign cryptogamic malady. Symbiosis 
for him represents the immunity realized by phagocytosis. 
Burgeff on theoretical grounds considers that both orchid and 
fungus must benefit by increased power of reproduction. He is 
in general agreement with Stahl as to the nature of the benefit 
the flowering plant receives. The union arose originally from 
the ability of the fungus to take up carbon compounds from the 
soil. The function of the fungus in germination is to introduce 
a solution of carbohydrates into the seed by means of its 
enzymes. 
Most recent workers on ectotrophic mycorrhizas regard the 
fungus as parasitic. Fuchs* attempted to inoculate the roots 
of Abietineae by adding fungus spores to the soil. He did not 
succeed in his experiments, but regarded the vehemence with 
which the young plants cut off the infected cells as an effort to 
prevent the attacks of a parasite. 
Weyland} introduced the microchemical method of studying 
the question and it is probable that from such studies a clearer 
idea of what is really taking place will be obtainable, by the 
determination of the localization of nutriment. He considers, 
that the fungus in an ectotrophic mycorrhiza is really a parasite 
and has nothing to do with symbiosis. 
* J. Fuchs, Ueber die Beziehungen von Agaricineen und anderen humus- 
bewohnenden Pilzen zur Mycorhizenbildung der Waldbaume. Bibliotheca 
Botanica, LXXvI (19IT). 
¢ H. Weyland, Zur Ernahrungsphysiologie mykotroper Pflanzen. Jahr. f. 
wissensch. Bot. Li, pp. 1-80 (1912). 
