478 THE SOOTY MOULD OF CITRUS TREES, 



shaped and sometimes branching pycnidia. They are distinct in 

 appearance and contents from the two preceding forms, and may 

 be ver}^ common. 



They are so varied in character that it is difficult to describe 

 them generally, but a special form may be selected, as in 

 fig. Qa. It is an elongated, irregularly shaped body, the lower 

 three-fourths of a pale green coloxir with a tinge of yellow, 

 and the upper fourth of a decidedly darker tint. The upper 

 fourth is slightly swollen and tapering towards the free end, with 

 a round opening at the very apex, and contains the spores. 



The lower portion tapers towards the base and bulges on one 

 side towards the centre, after which it narrows into the upper 

 portion. It is enveloped by and has hyphai grovving out from it, 

 while the upper fourth is bare. The wall is faintly marked out 

 into small irregular areas. The size is 240 x 75 fi, and the 

 terminal smooth portion is 66 x 56 fx. There is no decided line 

 of distinction between the upper and the lower portion, only the 

 darker colour is confined to the upper portion. 



Other specimens are common enough, which are just straight 

 or curved cylindrical bodies, branched or unbranched, sometimes 

 swollen at the base, and generally becoming paler in colour 

 towards the tip. They may reach a length of 530 fi, and narrow 

 down to a breadth between 20-30 fi. The wall is evidently com- 

 posed of elongated, jointed filaments, arranged end to end. The 

 spores escape by the opening at the apex, and are hyaline, rod- 

 like, rounded at the ends, minute, imbedded in a gelatinous matrix, 

 4-6| X 1-2 fi, average about 5|-6 x l-i-2 /x. It will be observed 

 that the spores resemble spermatia closely, but the capsule is 

 diiferent. 



(7) Pycnidid. — These are not quite so common as the preceding 

 in the specimens examined by me, but they are plentiful enough. 

 They are generally somewhat flask-shaped or bottle-shaped bodies, 

 branched or unbranched, dark coloured but often pale green 

 towards the top, with walls resembling those of the preceding, 

 and mouth usually fringed with hairs. There is considerable 

 variety in the shape. It may be elongated and cylindrical, or 



