A Mycorhiza from the Lower Coal-Measures. 
BY 
F. E. WEISS, D.Sc., F.L.S., 
Professor of Botany in the Victoria University of Manchester. 
With Plates XVIII and XIX and a Figure in the Text. 
ALL who have investigated the microscopic structure of fossil plants 
are familiar with traces of fungal hyphae and occasional fungal 
sporangia in and around the plant-remains. An excellent critical account 
of our knowledge of such fossil Fungi will be found in Seward’s ‘ Manual 
of Fossil Plants ’ (’98), in which he has not only recorded the Fungi de- 
scribed by Williamson, Renault, Conwentz, and other observers, but discusses 
their possible systematic position. In summing up our knowledge of this 
group of plants, he remarks that ‘we have fairly good and conclusive 
evidence of the existence in Permo-Carboniferous times of Phycomycetous 
Fungi.’ 
Judging from the appearance of the tissues in which these Fungi are 
found, one is led to the conclusion that they were for the greater part 
of a saprophytic nature. This would seem more particularly so in the case 
of the fossil plants from the English Coal-Measures, the internal structure of 
which is so fully known from the remains found in the nodular concretions, 
the so-called ‘coal-balls’ of the Bullion Coal. In these coal-balls, which, 
according to Lomax (’02), were probably not formed in situ, the plant- 
remains are often of a very fragmentary character, and show traces of 
having undergone considerable decomposition. The tissues are often 
penetrated by Stigmarian rootlets, and show signs of having been bored 
by wood-eating animals. They also show not infrequently internal mycelia, 
while apparent fungal sporangia are found both within the fossil plants and 
in the debris lying between them. Indeed, the conditions under which these 
nodules were formed would seem to have been most favourable for the 
growth of saprophytic Fungi. Some of the fossil Fungi, however, from the 
silicified nodules at Grand Croix which have been described by Renault (’83) 
and Bertrand (’85), and more recently by Oliver (’03), seem to have been of 
a parasitic nature and to have belonged probably to the group of Chytri- 
diaceae. One form, indeed, which appears to have been parasitic on the 
Annals of Botany, Vol. XVIII. No. LXX. April, 1904.] 
