390 Petch . — The Genus Endocalyx , Berkeley and Broome . 
gather this second species, but it is so fragile that it could never reach the 
describer in an undamaged condition. It was sent by Thwaites to Berkeley 
and Broome in the same collection as the specimens they named Endocalyx , 
but they failed to recognize that it was at all related to the latter, and 
named it Melanconium melanoxan thu m . Cesati gave the same name to 
specimens collected by Beccari at Peradeniya, but all recent describers 
appear to have overlooked the fact that it had been named before. 
Endocalyx melanoxanthus (B. & Br.) 
(. Melanconium melanoxan thum, B. & Br.) 
This species is especially abundant on the midrib and sheath of decay- 
ing palm fronds, more particularly Cocos nucifera and Oncosperma fascia da- 
tum. In its usual damaged state it presents a patch of scattered black 
spores, mixed with thin, irregular yellow scales ; and beneath this mass are 
circular cavities in the tissue of the host plant : it answers then to Berkeley 
and Broome’s brief description, ‘ Pustulis orbicularibus erumpentibus floccis 
granulisve flavis cinctum : sporis subglobosis angulatisve’ (Journ. Linn. Soc. 
14 (1875)- p- 89). 
As the decaying palm fronds afford a favourable medium for the growth 
of many other fungi, it is difficult to obtain exact evidence concerning the 
early stages of this species, more especially as all the individual fructifica- 
tions of its extensive colonies appear to mature at the same time. The 
earliest determinable stages are indicated by a slight elevation of the cuticle 
of the host plant : a section through one of these pustules shows that it 
consists of a spherical mass of fungus tissue occupying a cavity excavated in 
the epidermis and the underlying tissues, but not more than 150 /x deep. 
This mass is entirely pale yellow, and consists of fine hyphae approximately 
parallel to each other and perpendicular to the surface of the host (PI. XXIV, 
Fig. 1). Before the pustule bursts, spore formation commences in the 
centre of the sphere, so that a vertical section through an older pustule 
shows a blackish central circle of spores completely surrounded by a narrow 
yellow zone of hyphae. When the pustule opens, the ruptured cuticle forms 
a ring the height of which depends to a great extent on the nature of the 
host plant. On palms whose epidermis decays fairly rapidly, the open 
pustule is practically level with the surface of the frond, but in Oncosperma 
which has a tough, polished, persistent cuticle, the latter forms a ring which 
causes the open pustule to be raised about 100 /x. This is an unimportant 
detail, but it has to be insisted upon, because it is on just such details that 
species have been established from gatherings of tropical fungi. If the 
cuticle is light coloured, the open pustule is surrounded by a blackened 
area, but this is not noticeable on Oncosperma in which the cuticle is dark 
red-brown. 
