156 Scientific Proceedings, Royal Dublin Society. 



other willow plants in the neighbourhood. The pycnidia are, 

 from the practical point of view, sources of infection. On searching 

 mycological literature for anything comparable, I was struck by 

 the great similarity between these pycnidia and the ones described 

 and figured by Prillieux and Delacroix in the canker disease of the 

 sweet or Spanish chestnut in France. Some 300 acres of sweet 

 chestnut grown as coppice for the supply of rods for laths and 

 for barrel-hoops were attacked almost throughout the wood, and 

 the value of the rods reduced quite 50 per cent, in consequence. 

 The account these authors give agrees remarkably with that which 

 I have given in the case of the willow — the same reduction 

 in the yield of rods, loss of splitting and bending properties in 

 those gathered. 



The authors called their fungus Diplodina castanece, Prill, et 

 Delac. ; and a name which naturally suggested itself for the Irish 

 willow canker was Diplodina salicis. This name I found, on con- 

 sulting Saccardo's " Sylloge Fungorum," had been given by Wes- 

 tendorp to a fungus found and described by him growing on 

 the weeping willow in Courtrai, the centre of the flax-retting 

 industry in Belgium. Unable to see either Westendorp's descrip- 

 tion or his specimen, I wrote to Professor 0. van Bambeke, of Ghent, 

 who, with the greatest kindness, sent me a small piece of the type 

 specimen as collected by Westendorp, a copy of the only figure 

 given, and of the detailed description published by the author 

 under the title " Cinquieme notice sur quelques Hypoxylees, 

 inedites ou nouvelles pour la Flore de la Belgique." Comparison 

 between Westendorp's specimen and the Irish one shows that the 

 two are distinct. In the Belgian specimen the pycnidia are scat- 

 tered over the surface of the willow-stem, not collected on definite 

 canker-spots, as in the Irish one. The pycnidia are also differently 

 shaped, and contain much larger conidia. 



Kickx 1 places Westendorp's species in the genus Diplodia, and 

 gives a description, for a copy of which I am indebted to Professor 

 Bambeke. I quote only the last few words : — " Spores (conidia) 

 ellipsoides, etroites, obtuses, hyalines, offrant au milieu, d'apres 

 l'auteur, une cloison transversale que nous n'avons pu aperce- 

 voir." I have been able to satisfy myself, from the material sent, 



1 " Flore Cryptogamique des Flandres " (Gand, 1867), tome 1, p. 394. 



