330 Ward . — Recent Publications bearing on the 
in the functioning of the mycelium as root-hairs. Since 
the whole surface of the root is covered by the mycelium, 
water and dissolved substances can only reach the former 
through the latter, and the extensive ramifications of the 
outlying mycelial strands and hyphae in the soil no doubt 
achieve the work of true root-hairs. Frank also sees in 
the enlargement of the epidermis-cells of the root and their 
enclosure in fine hyphae an adaptation which probably works 
to the same end. We are therefore to look upon the 
root-fungus as the sole organ for the absorption of water 
and materials from the soil, in the cases concerned. Frank 
therefore contrasts the mode of nutrition of Cupuliferae, as 
heterotrophy , with that of ordinary land plants — auto- 
trophy . 
The comparison with the symbiosis of Lichens is evident, 
and it need only be remarked that just as the gonidia of a 
Lichen are not incapable of independent existence, so the 
roots of oaks, beeches, and other Cupuliferae may be grown 
independently for years in water-culture. 
Whether the Cupuliferae can develope under ordinary 
conditions, with their roots in the soil, in the absence of 
the ‘ nurse fungus, 5 and whether they would do better or 
worse simply cannot be decided, because there appear to 
be no Cupuliferae free from the fungus. 
Just as Lichen-fungi will not flourish without the host 
Alga, so the root-fungus seems to be dependent on the 
tree : no efforts to cultivate the mycelium artificially have 
succeeded. 
Such is, shortly abstracted, the story of the Mycorhiza as 
told by Frank in the first instance. 
This was soon followed by two more or less critical notes, 
first by Woronin 1 , and then by O. Penzig 2 . Woronin writes 
to the effect that he had known the ‘Mycorhiza’ for two 
years, having found it in Finland when investigating the 
biology of certain edible Boleti , &c. 
1 Ber. d. deutsch. Bot. Ges., 1885, p. 205. 
3 Ibid. p. 301. 
