[VoL. 3 
4 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
gest Rhizoctonia, and it would not be strange that sclerotia 
were absent under the conditions. 
Prompted apparently by the account just referred to, and 
based somewhat upon that, von Thümen (’82) reports upon 
the ‘‘Vermehrungspilz,’’ and this appears to be the first defi- 
nite account of the organism from central Europe. His de- 
scription of the mycelium adds somewhat to that of Therry 
and Thierry, and like them he found that “* * * die Unter- 
suchungen nichts weiter ergab, als die Anwesenheit zahl- 
reicher, spinnwebendünne, weisslicher oder braunlicher My- 
celfüden, von irgend einer Fruetifieation aber trotz genaues- 
ten Suchens auch nicht die mindeste Spur aufzufinden мат.” 
Whatever may be the interpretation of these two sets of ob- 
servations they emphasize (1) the rapidity of growth and vio- 
lence of the attacks of the organism concerned and (2) the 
presence of a mycelium as the only stage of the associated 
organism. 
It appears probable that the disease which came to be known 
as ‘‘maladie de la toile?" in France is the same as that re- 
ferred to by Therry and Thierry (282); nevertheless, such ob- 
servations as are reported during the next fifteen years leave 
the question of a causal organism in an unsatisfactory state. 
Mangin (794) refers to ‘‘la toile" as the disease due to a fun- 
gus occurring both in the greenhouse and in the open, pro- 
ducing a decay of leaves and branches, especially at or near 
the surface of the soil. Recalling what has already been said 
regarding this fungus it is significant that he remarks: 
“Quand la Toile est bien développée, les filaments mycéliens 
agglutinent les fragments de terre et deviennent trés visibles." 
Collecting material from the affected area he found that in a 
few days conidiophores of Botrytis appeared on the dead 
leaves. With cultures of the Botrytis he reproduced a dis- 
ease in lettuce. Since, however, Botrytis cinerea might oc- 
eur upon any debris, and since it also produces a disease of 
lettuce, it does not follow, of course, that it is the fungus re- 
sponsible for the troubles here referred to. From the de- 
scription of the effects, one is inclined to reject the idea that 
Botrytis is concerned in this ease. In the same year Prillieux 
