32 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



rather anomalous in size and form for this kind of spot, since they are 

 fusiform and curved (10 n long). 



The species has also been observed in Italy. 



(hrvillca, v. p. 50; Sacc. Syll. iii. 2717. 



Hazel-leaf Blotch. 

 Gnomoniclla Coryli (Batsch). 



This fungus has long been known on Hazel leaves, and has had its 

 name changed a great many times. It occurs on the living leaves in 

 black shining raised patches on the under surface, resembling little drops 

 of pitch. Each cluster is composed of several receptacles arranged in a 

 circle and immersed in the black stroma, with long projecting necks, 

 each neck surrounded by a white fringe-like collar. 



Within the receptacles are a series of cylindrical tubes, or asci, which 

 enclose the sporidia, eight of which are contained in each tube, and each 

 one is colourless and oval, without any division (7x3 /Lt), 



When these leaves fall to the ground the sporidia soon arrive at 

 maturity, and are discharged to fulfil their duty in the perpetuation of 

 the species. 



There is an earlier and imperfect stage (Leptothyrium Coryli), in 

 which the sporules are free in the receptacles (18 x 2 /x), but the precise 

 nature of their relationship is not distinctly known. 



Sacc. Syll. i. 1590 ; Cooke Hclbk. No. 2736 ; Tubcuf, Dis. 224. 



The above is not common enough or harmful enough to cause the 

 least anxiety. 



Root Fungi. 



It has been known for the past fifty years — and Berkeley was con- 

 tinually reverting to it, and asserting it, in the pages of the Gardeners' 

 ( 'hronicle — that the white fleecy mycelium often seen about the roots of 

 orchard trees was injurious to them ; that it originated from dead stumps 

 and buried wood, and attacked the roots of living trees when it was no 

 longer a saprophyte, but became a parasite and crept up between the 

 cortex and the wood, and ultimately killed the tree. This is now more 

 generally acknowledged to be true, whatever the ultimate development of 

 the mycelium might be, possibly some Agaric, and that dead wood and 

 dead roots left in the soil when young trees are planted will sooner or 

 later prove the source of great injury and destruction. It has been left 

 to more recent times to demonstrate that mycelium which originally, and 

 in ordinary cases, was only a saprophyte could under favourable con- 

 ditions become a dangerous parasite. 



Under such circumstances it will be seen that trees should never be 

 planted in Boil which contains the remains of dead stumps or dead roots, 

 and whenever growing trees are discovered with this mycelium at the 

 roots they should be removed and the soil sterilised before it is planted 

 a.^iin. Diseased roots, if not too far infected, should be cleaned and 

 pruned before replanting, and well washed with some fungicide, when, in 

 onn en e . they may possibly recover ; otherwise they should be burnt 

 forthwith. 



