FUNGOID PESTS OF CULTIVATED PLANTS. 199 



been observed elsewhere. The black prominent receptacles, like pins' 

 heads in size, thickly cover the green leaves, over entire branches, so as 

 speedily to complete the work of destruction. The receptacles are nearly 

 globose, immersed in the leaves, and enclose a gelatinous nucleus, which 

 consists of a mass of cylindrical tubes or asci, each containing eight 

 sporidia. These sporidia are elliptical, colourless (18-20 x 5-6 /i), and 

 divided by a transverse septum into two cells. Asci (70-75 x 12-14 fj) 

 without paraphyses. 



This is so deep-seated an endophyte that it is doubtful whether the 

 application of fungicides would make any impression. We can only 

 advise the removal of all affected twigs, as soon as discovered, and burning 

 them. 



Sacc. Syll i. 1836 ; Grevillea, vi. 128. 



FUNGOID PESTS OF FOREST TREES. 



We have illustrated some of the most prominent pests of forest trees, 

 but they are very numerous, and not of so much interest to horticulturists 

 as other sections ; hence we have not considered it incumbent upon us to 

 enumerate other than those which are most likely to present themselves 

 under ordinary circumstances. Those persons who are specially interested 

 in forestry will not find our list by any means exhaustive, but simply 

 suggestive, except in so far as regards the trees which surround, or are 

 included in, large gardens and shrubberies. 



OCHKY MAPLE SPOT. 

 Phyllosticta Aceris (Sacc.), PI. XIX. fig. 1. 



The ordinary leaf-spots are not any considerable damage to forest 

 trees, unless they are unusually plentiful ; in any case they must be 

 regarded as diseases. The common Maple is very subject to one which 

 forms nearly circular bleached ochraceous spots on the leaves, over which 

 are scattered the dot-like receptacles immersed in the tissues. The 

 sporules, which are contained within these receptacles, are ovoid, and 

 rather small (5x8/i) with two guttules, which are extruded from the 

 receptacles through a minute orifice when mature. 



The above species was first recorded for Italy, and in no other 

 country except Britain. 



It is almost impossible to suggest any remedy for these leaf-spots, 

 since spraying is out of the question with objects of this size, although it 

 may be adopted whilst the trees still remain as seedlings. 



Sacc. Syll. iii. 61 ; Grevillea, xiv. 71. 



Quite twenty other species of leaf-spot, caused by Phyllosticta and 

 Septoria, have been recorded in different parts of the world on leaves of 

 Acer. 



