520 Schivartz.—Parasitic Root Diseases of the J uncaceae. 
Entorhiza Cypericola. 
The life-history of this fungus, which causes the formation of the root 
tubercles, was studied and described in 1884 by Weber. My own experience 
has enabled me to confirm the greater number of his observations, though 
whereas he worked with the tubercles on the roots of J. bufonius , I have 
used those on J. articulatus and lamprocarpus , finding these easier to 
obtain. I have had no opportunity of seeing the disease on Cyperus 
favescens. 
The tubercles vary considerably in size ; the largest I found on J .bufonius 
were about 5 mm. long and unbranched, while those on J. articulatus were 
sometimes as much as 10 mm. in length, and frequently branched ; also 
they were proportionately thicker than the tubercles on J. bufonius. The 
tubercles themselves are the swollen, modified ends of roots ; in section they 
show a central stele surrounded by an enlarged cortex, all the cells of which, 
except those comprising the outer layer or perhaps two layers, are dominated 
by the fungus, being for the most part filled with spores in various stages 
of development. In longitudinal section it is observed that the oldest 
spores occupy a position near to the base of the swellings. The mycelium 
of the fungus is within the cells of the host-plant or partly intercellular; 
the intracellular hyphae are very delicate and much twisted in corkscrew 
fashion. The spores are formed as terminal swellings of these hyphae ; at 
first they are white and glistening and binucleate, afterwards they thicken 
and take on a brown coloration, and when ripe they have two coats, the 
outer or epispore being spiny, and in general microscopic appearance they 
resemble typical Ustilago spores. 
The tubercles are cream in colour when young, but turn brown or 
black when the spores ripen; those gathered in the autumn from the 
annual bufonius plants are mostly black. There is no formation of cork 
round the tubercles of the Juncaceae, as is usually the case in other root- 
tubercles, e. g. those of Elaeagnus. 
The mode of infection appears to be by the entry of conidia into the 
root-hairs as is shown in Fig. 17 ; these conidia multiply in the hair which 
they thus travel down, and, after entering the root, give rise to hyphae. 
Most plants from infected ditches show root-hairs of this nature, whereas 
those from healthy or non-infected places only have root-hairs of the normal 
type; it therefore seems probable that these conidia-containing hairs 
represent the stage of entry of the parasite. Weber does not state how the 
fungus gains an entry into the root. He was successful in germinating the 
spores after a winters rest; having kept the tubercles in the open in moist 
sand through the winter, he observed germination in the February of the 
following year at the moderate temperature of io° C. These spores 
germinated when sown in water: Weber, however, obtained better results 
