ROYAL GARDENS, KEW. 
BULLETIN 
OF 
MISCELLANEOUS INFORMATION. 
No. 109.] JANUARY. [1896. 
CCCCXCIV.—ROOT DISEASES CAUSED BY FU NGI. 
Amongst the numerous root diseases of various plants cuted by 
parasitic fungi, none are better known, or extending over a greater area 
than the Pourridié of the French, which occurs in France, Italy, 
tiere, Austria, South-West ‘Germany, and has recently been 
ecorded from three widely separated localities in Britain. The 
fangs causing this disease is called Dematophora necatriv, Hartig, 
which frequently devastates vineyards and orchards; its —À Ar how: 
ever, are unfortunately not confined to vines and fruit trees ; 
beans, beet, &c., are also destroyed, and Hartig states me the raliis 
soon ills young maples, oaks, beeches, pines, and spru 
mycelium first attacks and kills the youngest rüodeh and then 
enters into the Ar branches of the root, in which it rapidly spreads 
ilar network of slender strands; finally bursting 
through the cortex and enveloping the roots in a snow-white, fluffy 
mycelium, here and there, running into slender cord-like strands, 
which traverse the soil, and by this means — rom one tree to 
another. At a later stage of development, numerous minute, black 
€ one of mycelium or sclerotia are Sarees in the cortex of the 
roots, from each of these spring several slender spines, each of which 
bears an inin crop of conidia or reproductive bodies at its tip. In 
addition to the re mycelium, a very characteristic pale brown or 
ed o 
olive mycelium is also present on the surface of the roots, form 
septate or jointed t threads of variable thickness, n: pear-shaped 
rte eiat x intervals; these swollen portions finally become free by the 
e of the intermediate portions of the myeelium, and form 
bodies ccm of germinating and giving origin to a new crop of myce- 
lium. Under certain conditions some - the Scito instead of p 
ducing the spine-like bodies bearin nidia, become converted into 
hollow spheres or — —Ó in i shaik interior numerous minute 
reproductive bodies or stylospores which germinate at once and pro- 
duce new plants. Finally, the highest, or ascigerous form of fruit is 
rare, and only dev ae “we old trunks that have been dead and decayed 
for a long a Up to the present the last-mentioned form of fruit has 
only been t with i in omm nce, and its structure is such that the fungus 
proves to alos to the T'uberacei or truffle family. 
u 90349. 1875—1/96. Wt.308. E.&S. A 
