TREE ROOT DISEASES. 3 

the oidium of the vine are terrible pests in New Zealand, and the settlers have more 
to fear from fungus growths than insect pests.” 
As previously stated, the material received from New 
Zealand was, in the first instance, referred to Dematophora 
necatyzx. Further development of the fungus, and the 
receipt of additional fruiting specimens from the same 
country, showed that this was a mistake. Neither does the 
fungus belong to any known species. It will, therefore, be 
described as new, under the name fosellinia radiciperda. 
On arrival, the diseased roots and infected soil were per- 
meated throughout with delicate white strands of mycelium. 
‘The roots were laid on the surface of a thin layer of sterilised 
leaf-mould kept moist and protected by a bell-jar. Two 
boxes, each about one foot square and six inches deep, were 
hlled to within an inch of the top with sterilised leaf-mould. 
A thin layer of the infected soil was sprinkled on the surface 
of the soil in each box ; in addition, a portion of the root of 
an “Orange Pippin” apple tree was thrust into the soil of 
one box, and two beech seedlings planted in the other. 
Finally the boxes were covered with glass to prevent con- 
tamination from floating spores of fungi, kept damp, and 
placed at the foot of a wall having an eastern aspect, where 
they remained from June till the end of August. At the 
end of a month the roots under the bell-jar were densely 
covered with a snow-white, fluffy mycelium, giving off nume- 
rous delicate white strands which spread into the leaf- 
mould. By degrees the mycelium on the roots graduallv 
changed to a pale brown colour, and under the microscope 
the strands of mycelium showed pear-shaped swellings at 
intervals—hitherto considered as characteristic of Demato- 
phora necatrix—represented on the plate (Fig.7). Viala states 
that in D. xecatrix these swollen portions gradually become ~ 
clobose and free if the mycelium is kept very wet, and form 
reproductive bodies —chlamydo-spores—capable of ger- 
minating and producing new mycelium. I was not suc- 
cessful in producing this result with the mycelium of the 
New Zealand fungus, although presumably, from analogy, 
this failure may be due to a lack of some essential factor. 
At a still later stage numerous minute sclerotia burst through 
