ill 



'gi*owth, namely a vertical narrow canal in the innerbark, very neat* 

 to the cambium, could not possibly be imitated artificially. 



Fig. 1. (Natural size). Gum producing peachalmond in September, whose 



summit is cut off; the gum from the gum canals is after drying, swollen by 



moistening with cold water. 



Much more common and interesting than the animal parasites are 

 the gum producing Fungi of the Amygdalaceae, five of which are 

 found in our country. ') The commonest and most vigorous is Cor- 



1) Coryneum bevjerinckii Oudemans, Gytospora leucostoma Persoon, Monilia 

 cmerea Bonorden, Monilia fructigena Bonorden and Botrytis cinerea Persoon 

 (see Rant, 1. c. p. 88). German authors also mention bacteria as instigators of 

 gummosis, I never found them. 



54 



Proceedings Royal Acad. Amsterdam. Vol. XVII. 



