Manchester Memcits, Vol. Ivii. {igi^), No. \] 



the stem and the petiole the pericyclic fibres of the 

 vascular bundles attacked by the fungus are almost 

 entirely devoid of thickening. A comparative study of 



Qo^ 



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Text-fig. 6a. Collenchyma cells in unafi'ected area with 

 cellulose thickening indicated. 



B. Similar cells pepurated by mycelium of the fungus 

 at an early stage. 



c. Similar cells with mycelium between at a later stage, 

 and the thickened areas on the walls diminished 

 and almost completely disappeared near the teleuto- 

 spore sorus. x loO. 



