ROSKLI.1NIA. 2Ul 



propagated through the soil from plant to plant. Then- is a 

 rest ing- stage in the form of chambered sclerotia, black tuber- 

 like bodies which have their origin in the cortical parenchyma 

 of the roots and break out through the cortex. Reproduction 

 is effected throughout the summer by means of eonidia, pro- 

 duced from a mycelium which vegetates on the surface of the 

 soil; this mycelium bears conidiophores with whorled brain.-h-~. 

 from which the conidia are abjointed. 



The perithecia are spherical structures compo.-ed of hyphae 

 with walls which swell up in a gelatinous manner. At first 

 the inside of the perithecium is a gelatinous mass containing 

 the paraphyses and the rudiment of the ascogonium. AJS the 

 asci are developed, they push their way into the gelatinou- 

 mass amongst the paraphyses. Each ascn.- is a Inn- chili- 

 shaped tube, the apex of which is thickened and stains blue 

 with iodine, showing at the same time a canal piercing it. 

 The ascospores are canoe-shaped with sharp ends, and when 

 mature have a dark brown colour. The spores germinate in 

 spring: in water-cultures germ-tubes are emitted twenty-four 

 hours after sowing. The spores open by a longitudinal slit, and 

 a germ-tube emerging from each end branches into a mycelium 

 which soon takes on the form of a rhizoctonia-strand. Infection 

 takes place thi-mi-h the tender non-cuticularized apices of roots. 



The fungus may be combated if di.-cased portion- of seed- 

 beds are isolated by means <>f trendies dug round them. It 

 boards soaked in carbolic acid or coal-tar ale placed upright 

 in the trenches, greater certainty will be secured that the 

 disease does not spread. 



Several species of //// /:/(-///*/, probably related to the above, 

 may now be briefly considered. 



Rhizoctonia violacea Tul.Mt'.S. America), Hoot-fungus of 

 lucerne and clover. The presence of this di>ease i- >|iown in 

 summer by the plant- withering, and finally dying. The mveelium 

 lives inside the roots, ami covers them externally with violet 

 Coatings "M which the M-len.tia appear as black tube]-. 



On plant- \vitli >c-|.-iut i;i, Fu. -k'l found p\ vnidi.t ;in<l |-rit In. ia .,(' 

 Leptotphaeria ' 7V /</'//'<.<///</ t'a i /<'/.<."//<'<//////: <ir<in<in.<; \\lirtln-i- tin- 



\;n ..... - t"ini> \\i-ii- ii-l.iti-il ...iiM nut, li"\\,-\i-i, !" ili-t 



1 l.'o>trii|i. ('in/- ;.,.,. ,/./-,/ nn<i<i. ml- Si'iiiii/.. Jn ,.//,i i /,'/, 1 



'l'uhi>in-, I HH-II /ii/fi'i/it- i. I'l. 1\. .unl \\ . l^.'il. 



