256 Weiss.— A Mycorhiza from the Lower Coal-Measures . 
fronds of Alethopteris aquilina , Magnus (’ 03 ) considers sufficiently like the 
recent form Urophlyctis to warrant its inclusion in that genus. 
From the observations so far made we are able to picture to a certain 
extent the modes of life of the Fungi in Palaeozoic times, and we come 
to the conclusion that they differed very little from those of recent Fungi. 
But, besides leading saprophytic or parasitic existence, Fungi are at the 
present day also found living together with green plants in a state of sym- 
biosis, in which they do not destroy the tissues of the green plant, but seem 
rather to be of some use to it, while at the same time they derive some 
benefit from the green plant. Living in such mutual relations with algal 
cells, the Fungi form the group of organisms known as Lichens, while when 
they inhabit the roots or root-stocks of many higher plants they form the 
so-called mycorhiza, the significance of which is still under discussion. 
Remains of Lichens are, according to Schimper and Schenk (’ 90 ), known from 
the Tertiary period, some of them being preserved in Amber ; but none 
have so far been recorded from Secondary rocks. Mycorhizae, on the other 
hand, have to my knowledge not been described in a fossil condition. Yet, 
at the present time this peculiar association of Fungi with the roots of 
higher plants is a fairly widespread phenomenon. This is perhaps more 
particularly the case in tropical forests, where, according to Janse’s investiga- 
tions, sixty-nine plants out of seventy-five chosen from various divisions of the 
vegetable kingdom had their roots inhabited by apparently symbiotic Fungi. 
Whatever may ultimately turn out to be the significance of these endo- 
phytic Fungi, there can be no doubt that this mutual adaptation represents 
a considerable specialization of the two organisms forming the Mycorhiza. 
The latter might, therefore, be expected to have arisen at a comparatively 
recent period in the evolution of plants. But apparently this form of 
symbiosis is of considerable antiquity, for it seems to have existed as 
far back as the Lower Coal-Measures. I am conscious that this announce- 
ment will very naturally meet with some scepticism ; nevertheless, I 
venture to think that the evidence which will be brought forward in the 
following pages warrants the conclusion that this highly specialized mutual 
adaptation of Fungus and cormophyte did actually exist in the Palaeo- 
zoic age. 
The root or rhizome in question I found on two slides in the Cash collection 
of Coal Measure plants in the Manchester Museum, Owens College (slides 
No. Q527 and Q539), both from the Halifax Hard Bed, which, according to 
Binney (’ 62 ), must be correlated with the Bullion Mine of the Burnley district 
and the Gannister Mine of Dulesgate, Todmorden. These three seams of the 
Lower Coal-Measures are characterized by the possession of the nodular 
concretions (coal-balls) referred to above, and it is from one of these that 
the preparations were made. On communicating my view of the nature of 
these specimens to Dr. Scott, he very generously placed at my disposal 
