124 MICEOSCOPIC FUNGI. 



CHAPTER X. 



WHITE EUSTS. 



LLUSION has already been made to the im- 

 portant memoir recently published by Dr. de 

 Bary. ^^ White rusts ^^ occupy a conspicuous posi- 

 tion in that memoir^ and the experiments therein 

 detailed^ with the conclusions arrived at^ will be 

 largely drawn upon in furnishing the present chap- 

 ter. Whilst believing that we have fairly repre- 

 sented the views^ and faithfully narrated the story 

 of research^ if not literally^ but denuded of some 

 technicality^ yet in such manner as to convey the 

 sense of our author^ we claim no originality or 

 merit save for the garb in which it appears^ without 

 addition^ stricture^ or confirmation of our own. 



What is the external appearance presented by 

 the ^^ white rust^^ of cabbages^ and allied cruci- 

 ferous plants^ is soon told. During summer and 

 autumn it occupies the surface of the leaves and 

 stems of the shepherd^s purse {Gapsella hursa-paS" 

 toris)y with elongated narrow white spots like 

 streaks of whitewash (plate X. fig. 198)^ and later 

 in the season the leaves of cauliflowers and cab- 

 bages become ornamented with similar patches, 

 arranged in a circular manner (plate X. fig. 199), 

 forming spots as large as a sixpence. Wherever 



