6c>7 
and their Mycorhiza . 
their former diameter ; in the latter cells the hyphae appear to have entered 
the cell and grown around a central nucleus. PI. XLVII, Fig. 7, shows the 
beginning of such a stage, of which Figs. 8 and 9 may be later stages in the 
absorption of the hyphae. Dilations of the hyphae are apparent here also ; 
but the large bladder-like growths, which Groom has described, are not to be 
seen. In the cortex of the rootlets that are apparently full-grown, and are 
about to form a periderm, there are to be observed large knob-like growths 
with thickened walls that are apparently terminal on the hyphae, and 
are about *05 mm. in diameter (PI. XLVII, Fig. 6). These I take to be a form 
of resting-body which the fungus forms to carry it over the period during 
which the cortex will be sloughed, and before it has an opportunity of 
infecting a fresh rootlet. They are not unlike those swollen hyphae figured 
by Seward, but they are formed in definite connexion with the rest of 
the mycelium, and in roots which, there is every reason to believe, were 
healthily growing ones, and not detached fragments of decaying vegetable 
matter. Quite recently, while examining roots of Podocarpus cupressina , 
I have found exactly similar dilations terminal on the hyphae, in the cortex 
of the roots at the time that cork-formation had set in. This parallel 
I consider particularly useful, as it meets the possible objection that the 
bladder formations are sporangia of a parasitic fungus. 
All sign of spore-formation is lacking, though some sign might be 
expected to be present in either a saprophyte or a parasite. 
It is manifestly impossible to offer any suggestion as to the relationship 
or systematic position of the fungus ; and it is quite unsafe to formulate 
any theory of Phycomycetous relationship based on the general absence of 
septa. To quote Shibata, £ Das Fehlen der Querwande in den Hyphen 
beweist hier nichts, da die Septirung oftmals in intracellular-lebenden 
Mycelien ausbleibt.’ 
The relationship of the fungus to the lateral roots of Amyelon is 
a matter on which there may reasonably be some uncertainty. It is well 
known that the saprophytic fungi occur quite commonly with the remains 
of higher Palaeozoic plants. Seward (14) has given a collected account 
of them in the first volume of his e Fossil Plants ’, and there is also the large 
monograph by Meschinelli (7), though this is not confined to Palaeozoic 
specimens. They are omnipresent amongst decaying vegetation to-day, so 
that there is nothing to cause surprise that similar destructive agencies 
should have existed in the Coal Measure Period. 
The fungus in question, however, hardly gives the impression of being 
a saprophyte. In the first place the preservation of the material is against 
this, for it is equally good for both fungus and roots. These latter are 
in many cases admirably preserved, e. g. the root apex, and do not give the 
impression of being decaying pieces of vegetable matter on which the fungus 
was feeding, but rather sound and living rootlets, at the time that infection 
