584 
MR. H. M. WARD ON THE MORPHOLOGY AND THE 
The habit of these fungi, and the fact that no true Erysiphe had been found 
among the collections of travellers in the tropics, led Fetes 4 ’" to insist strongly on 
the known or supposed analogies between the two genera, and, Bornet following 
Fries, the Meliolas have thus come to be regarded as replacing the Erysiphes in 
tropical countries—as, in fact, “representative species.” Bornet added several facts 
to those already known concerning the coarser anatomy of the group ; but even his 
excellent and systematic memoir left large gaps in the knowledge of important details, 
and practically nothing was known of their development or of the formation of their 
“ fruit-bodies.” These and other gaps I hope to fill up to at least a large extent in 
the present essay. 
The appearance of this fungus as presented to the unaided eye, is much the same as 
that offered by Asterina and similar forms, and the reader may be referred to a 
recently published drawing of that fungus for a tolerably accurate idea of it.t The 
chief difference is that the black maculae presented by well developed plants of 
Meliola are more decided and thicker than those of Asterina ; all transitions are 
found, however, and, as with many other forms of epiphyllous Pyrenomycetes, it is 
impossible to detect exactly what fungus is present by a superficial examination. 
The fungus Meliola may be conveniently considered as composed of a mycelium, 
which supports appendages and perithecia, and which arises from spores developed 
within the asci of the latter. Bornet considered the “ receptacle ” as an equally 
important and distinct constituent, but this is perhaps unnecessary since, as will be 
shown, the so-called “ receptacle ” can only be looked upon as a more or less accidental 
development, so to speak, depending and following upon the formation of the peri- 
thecium. 
The mycelium, forming the chief part of the black patches found on the surface of 
the affected leaves, petioles &c., spreads in an irregularly stellate manner from a 
common centre or centres (see Plate 42, fig. 1). It is detached with comparative 
ease from the epidermis of the leaf, and bristles with fine, simple or branched, pointed 
appendages, of a black colour, which spring from the main liyphse, and from around 
the subglobular perithecia which are irregularly scattered over the surface. 
The main liyphse constituting this vegetative part of the fungus, are irregularly 
radiating, sinuous or zigzag filaments, closely appressed to the epidermis of the leaf, 
&c., and composed of cylindrical joints or cells placed end to end, and branching at 
angles of about 45 degrees (cf. Plate 42, fig. 2, and Plate 43, fig. 5). Their stiff and 
even brittle walls are deeply coloured brown or black, and thus obscure the view of 
their contents : sections and reagents prove these to be finely grained protoplasm, with 
or without oily drops in the interior. The diameter of the hypha is equal throughout, 
* ‘ Sumna Vegetabilium,’ p. 406: “Genus in foliis tropicis vulgatissimum ut Erysiplies in terns 
temperatis.” 
t Quar. Journ. Micr. Sc., October, 1882, plate 27, figs. 1 and 2. See also Bornet’s beautiful figures, 
Ann. des. Sc. Nat., ser. iii., t. xvi., plates 21 and 22. 
