33 2 Ward. — Recent Publications bearing on the 
in the Berichte der deutsch. hot. Gesell. for Nov. 19, 1885 1 , in 
which he insists on his claims to have ‘ discovered a hitherto 
unknown biological phenomenon in the nutrition of certain 
trees/ &c., &c. He points out that Woronin’s rejoinder as 
to Kamienski’s having already discovered the nature of the 
Mycorhiza is premature, since Kamienski only discovered 
mycelium overlying the roots, and denied the organic union 
of root and fungus. However, it seems unnecessary to enter 
into a criticism of the discussion as to priority, as it may 
be accepted that Frank was clearly the first to generalise, 
and to suggest in the wide sense the biological significance 
of the symbiosis. 
What is more important is, that Frank himself investigated 
the Monoiropa roots anew, and found facts beyond the mere 
association of fungus and roots described. He discovered 
that the hyphae of the fungus are not simply on the surface 
of the Monotropa root 2 , but enter between the cells: this, 
as in the case of the Cupuliferae, only takes place on those 
parts of the root behind the region of growth in length. 
Hence the Mycorhiza of Monotropa is, like that of the Cupuli- 
ferae, a case of organic union and symbiosis between the 
fungus and the root. 
Frank then proceeds to state : — 
(1) That the phenomenon which he at first thought 
confined to the Cupuliferae and a very few other trees pro- 
bably appertains to ‘ all trees under certain conditions.’ He 
finds a form of Mycorhiza on the roots of the Scotch pine, 
the Weymouth pine, the spruce, the silver fir, the larch ; 
also in Salicineae, alders, and birches, and in one case even 
on the lime, and Prunus spinosa. 
(2) That ‘ the Mycorhiza is formed only in a soil which 
contains humous constituents or undecomposed vegetable 
remains ; the development of Mycorhiza increases or di- 
1 Neue Mittheilungen iiber die Mycorhiza der Baume und der Monotropa hypo- 
pitys, pp. xxvii-xxxiii. 
2 In a foot-note Frank states that he has found a case of this kind on Andromeda 
polifolia. 
