3 
Mac Doug a /. — Symbiotic Saprophytism . 
material, and hence the transmission of these substances 
to the higher plant is comparatively easy. The exact 
metabolic relations of the two organisms is not yet deter- 
mined, although the mere contact of the protoplasts of the 
Fungus and those of the higher plant would imply some 
interchange of material. The higher plant surely affords 
some mechanical advantages to the Fungus, and to that 
extent at least the arrangement constitutes a symbiosis. 
With regard to the higher plant, therefore, I have temporarily 
termed this adaptation symbiotic saprophytism . The number 
of species that have attained complete saprophytism by this 
method is very large, while partial saprophytism in this 
manner is a widely spread feature of plant-life, though, as 
may be seen below, it is more common in tropical latitudes. 
Schlicht (36) examined 105 species growing in the north 
temperate zone in Europe, and found seventy to be furnished 
with mycorhizal adaptations of the roots. Among the 
number were such forms as Ranunculus , Beilis , and Tarax- 
acum. Janse (16) examined forty-four Dicotyledons, fourteen 
Monocotyledons, five Conifers, and six Ferns and Liverworts 
growing in Java, and found mycorhiza on all except one 
Dicotyledon, three Monocotyledons, one Fern, and one 
Equisetum : that is to say, sixty-nine out of seventy-five 
species taken at random were more or less saprophytic by 
means of mycorhiza. Hoveler examined seventy-two species 
of native and cultivated plants growing in northern Germany, 
of which twenty-four were symbiotic saprophytes (14). Among 
the number were some not exhibiting mycorhiza elsewhere. 
Wahrlich examined 500 species of Orchids in cultivation at 
Moscow, all of which he reported as exhibiting mycorhiza (41). 
This number has been increased by subsequent observations 
by other investigators. 
Identity of Fungal Symbionts. 
Many attempts have been made to establish the identity 
of the Fungi entering into mycorhizal structures. Tulasne 
noted the fact that Elaphomyces forms coatings on the roots 
