52 



trees and is probably also a saprophyte. Zimmermann 

 found it on old pièces of coffeewood, on dead cacaopods 

 and some other trees and also considers it to be sapro- 

 phytic. Cultures of Spicaria and of Fusarium of Nectria 

 hâve been given to the „Centralstelle fur Pilzkulturen" at 

 Amsterdam. 



Fungi on cankered trees in Ceylon and elsewhere. 



As has alrendy been said, Nectria is considered to be 

 the cause of Canker in ail countries, where the disease 

 has been observed. 



On a number of diseased patches C a r r u t h e r s found pus- 

 tules of small, oval, unicellular conidia; after some time 

 larger, multiseptate, . crescentshaped conidia appeared, and 

 at last perithecia of Nectria. From this he concludes, 

 that Nectria is the cankerparasite and that both forms of 

 conidia are stages in its lifehistory. 



This conclusion, however would only be warranted if 

 he had grown the fungus in pure cultures, and there seen 

 one form develop from another. As far as can be deter- 

 mined from his publications, he has not done so. 



It is true, that Carruthers records a séries of infection 

 experiments, where in many cases he produced the 

 disease in stems as well as in pods by inoculating them 

 with one of the three kinds of reproductive organs. But 

 since thèse inoculations were not made with-pure cultures, 

 and since the experiments were conducted on estâtes on 

 which the disease was prévalent, while no control plants 

 were kept (trees treated in exactly the same way as the 

 inoculated ones, except that no fungus was introduced), 

 thèse results are not so convincing as to remove the 

 doubt which yet remains on many questions. We may 

 consider some of thèse questionable points. It is possible 



