444 



Critical discussion of literature. 



As the disease discribed by Zimmermann') holds 

 an isolated place, I will first deal with this one, 



Zimmermann says it shows a very typical charac- 

 teristic, the „anker cellen". I am quife sure that I never 

 saw anything like them in this fungus, so the „spinneweb- 

 ziekte" must be something else, though the growth on 

 leaves and branches resembles in many respects the 

 silverthread. 



Zimmermann notices 1. c. page 50, that this .,spinne- 

 webziekte" cannot be identical with the Pellicularia Ko- 

 leroga, a disease desciibed by Cooke, which attacks 

 coffee in Ceylon. So I pass on to the next literature on 

 this subject, namely the fungimentioned by Cooke and by 

 Ernst. I hâve not been able to peruse Cooke's original 

 publication and so I had to be content with the informa- 

 tion which Delacroix ^ gives in his book, and with the 

 description given by Massée in his „Diseases of cultiv- 

 ated plants and trees". A short account of the fungus 

 is found in Kew Bulletin 1893, pag. 67. 



Though the gênerai description shows a rather close 

 resemblance to the silverthread fungus, yet there are 

 some important différences. 



In the first place I never noticed conidia, which Cooke 

 says occur in his fungus; the possibility remains that 

 their absence was caused by unfavourable cultural con- 

 ditions, but it is scarcely likely that the natural substratum 

 should never show them. 



Delacroix says in his description, pag. 69: „Quand 



1) Zi m m er m an n, 1. c. pag 46. 



2) Delacroix, Les maladies et les ennemis des Caféiers, Paris, 

 1900. 



