FUNGOID PESTS OF CULTIVATED PLANTS. 161 



Whether a Californian vine disease, which is attributed to Plasmodio- 

 phora californica, is the same as the present species, we are unable to 

 determine. 



Gard. Chron. June 17, 1893 ; Mass. PL Dis. p. 338 ; Mass., Ann.Bot. 

 ix. p. 421, pi. ; Tubeuf, Dis. p. 528. 



Another vine-root parasite was described some years ago under the 

 name of Eosslera hypogcza, which was found on vine roots after they 

 were really dead, not only in Austria, but in this country. They were 

 little rounded fungi, like the head and upper portion of a large pin, but 

 unfortunately, when they were submitted ta that eminent lichenologist, 

 the late Rev. W. Leighton, he pronounced them to be a well-known lichen 

 called Coniocybe pallida. 



Gard. Chron. Dec. 22, 1888, fig. 105 ; Thilm. Pilz. Wein. p. 210, 

 t. 4, f. 9. 



WHITE ROOT-ROT. 

 Dematophora necatrix (Hartig), PI. XIV. fig. 20. 



This root disease, which affects the vine as well as other plants, was 

 originally known by the above name, representing the imperfect condition 

 in which it is usually found. 



The mycelium spreads rapidly underground, and when it comes in 

 contact with the rootlets of a plant it kills them, and gradually works its 

 way upwards into the larger portions of the root. Sometimes, after 

 travelling upwards, it bursts through the bark at the base of the trunk in 

 a white woolly mass. 



During its progress minute sclerotia are formed, which originate dark- 

 coloured, rigid, bristly conidiophores bearing numerous conidia at their tips. 



Another kind of fructification is sometimes found on decaying roots 

 in the form of pycnidia, or conceptacles containing stylospores. 



The highest or ascigerous form of fructification is more rare, and 

 consists of large black perithecia which include asci and sporidia, and are 

 surrounded by the bristly conidiophores. In this condition it has been 

 characterised under the name of Eosellinia necatrix (Prill. & Del.). 



Spraying is out of the question in such a case, and no cure can be 

 hoped for when the mycelium is once established. If the disease appears, 

 the affected plants should be isolated by trenching around them. 



Hartig & Somer. Dis. p. 82, with figs. ; Viala, Hon. with 5 plates ; 

 Mass. PL Dis. p. 118, fig. 21. 



DISCOLOURED VINE LEAVES. 



Discoloured Vine leaves are continually turning up without furnishing 

 any clue to the cause. These are mostly discoloured in large bright 

 blotches, which are sometimes yellow, as in some forms of the " Californian 

 Vine disease ; " or dark red, as in the " Sicilian Folletage ; " or red, brown, 

 and yellow, as in the Italian " Mai Nero." They appear to give evidence 

 of some form of organic disease, and yet to evade all microscopical 

 scrutiny, and after many years to remain as great a mystery as ever and 

 consequently without the suggestion of a remedy. 



U.S.A. Eeport Dep. Agri. 1892. 



