1899} SOCIETY FOR PLANT MORPHOLOGY 129 
baceous sorts. This scarcity of individuals is especially marked 
in case of the higher fungi. 
Different types of plant diseases due to a common Rhizoctonia: B. 
M. Ducear, Cornell University, and F. C. Stewart, New York 
Experiment Station. A number of species of the sterile fungus 
Rhizoctonia have long been known as root parasites on a wide 
range of host plants. (1) Studies on a damping-off fungus of 
various seedlings have located the cause of the disease as a spe- 
cies of Rhizoctonia. (2) A fungus agreeing in structure with 
the latter has been the cause of a serious root-rot of sugar beets 
in New York during the past year, and the fungus identified with 
this disease seems to be undoubtedly Rhizoctonia Bete Kihn. 
(3) An important stem-rot of carnations is also found to be due 
to a fungus agreeing precisely in its characters with the beet 
Rhizoctonia. 
That the organism mentioned in each case is the cause of the 
trouble indicated has been demonstrated by experiment. Again, 
there is abundant experimental proof showing that the beet 
fungus and the carnation fungus are identical. The last named 
fungi also produce damping off, although not so abundantly as 
the fungus originally isolated from damped-off , seedlings. 
Experiments, however, indicate that these different types of 
diseases are all due to the same species of Rhizoctonia, the spe- 
Cific affinities of which cannot now be given with certainty. 
Peculiarities in branching, and the formation of tuft-like masses 
of hyphe, or of sclerotia, readily identify this fungus. Its 
Beart 
“nsitiveness to alkaline nutrient media suggests the preventive 
treatment. 
: he stem-rot diseases of the carnation: F. C. Stewart, New 
Experiment Station. Under the names “stem-rot,” or 
Yor 
a“ di oa ‘a 
Teas at least two distinct diseases have been confused. 
and ‘S caused by Rhizoctonia; the other is due to a Fusarium, 
is, 
inca perhaps, identical with Sturgis’ carnation stem-rot. Both 
Th. ‘re common in the field and greenhouse. 
© Fusarium attacks chiefly the stem and larger branches, 
