JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



consists of a small nearly globose receptacle with a minute pore at the 

 apex which encloses the fruit, or spores, of the fungus. When fully 

 mature these minute sporules ooze out at the orifice in the form of a 

 tendril and spread over the surface of the leaf. 



The sporules in the present species are elongated and threadlike, with 

 about two transverse divisions (60 x 3^ ^) of a very pale olive tint. 



Found generally throughout Europe. 



Sacc. Syll. iii. 2624 ; Cooke Hdbk. No. 1320 ; Seem. Journ. iv. f. 27. 



A large leaf-spot {Pliyllosticta pyrorum) is known in the United 

 State-, with much smaller sporules (10 x 2 /*). 



Apple-leaf Black Mould. 

 Coniothecium Quest ieri (Desm.). 



This mould was first discovered in France nearly half a century ago 

 on leaves of Cornus, and has appeared this season (1902) on fading leaves 

 of Apple, although we have grave doubts of its being any other than a 

 saprophyte. It occurs on the under surface of completely dead spots of 

 the leaves, or on thoroughly dead and brittle leaves. The tufts are 

 small and scattered in little black dots over the dead parts, but do not 

 occur upon the merely discoloured and fading leaves. 



The conidia are conglomerated in variously shaped clusters of from 

 two to eight cells (about 10 a* diam.), of a pale brownish colour, mixed 

 with occasional slender threads. 



Sacc. Syll. iv. 2442; Trans. Br. Myc. Soc. (1903), p. 15. 



Apple-thee White Mould. 

 Oidium farinosu/m (Cooke), PL X. fig. 2. 



This mould was first observed in 1870 and 1871 covering the young 

 kwigfl and leaves of Apple trees with a mealy coating of white mould, so 

 that they looked as if dusted with flour or powdered chalk. Since the 

 above it lias he-come sufliciently common. Although it is a true epiphyte, 

 r ifl capable of inflicting injury, causing the young leaves to curl, 

 phoMriwg their growth, and distorting the tender twigs. 



Tin iv is a thin and delicate but profuse mycelium from which ari-e 

 tin fertile! branches, which are elub-shaped and divided by transverse 

 Bpta into ihort joints, which gradually contract at the suture, and then 

 the top j<»int ha\ing acquired an elliptical form falls away as a conidium. 

 to be followed successively by the other joints, so that a continuous crop 

 of mature 0 midia is ensured. They are externally quite smooth and 

 eolourh ss (2H 30 x VI 



Tin- habit and structure of this mould are quite similar to the Oidium 

 of the \ine, that which precedes the Hose mildew, and the development 

 of the different species of ilryaiphv. 



In 1H!)0 this mould made it- appearance on Apple trees in South 

 Wric.i, and possibly it is the same species as one which is common east 

 Of the Mississippi in the I nited States. 



