South African Perisporiaceae. 
127 
Summary. 
The fungi belonging to the genus Meliola are true parasites, sending 
haustoria into the cells of the host. 
The most common type is that which lias a fine filament penetrating the 
cuticle and a small, globular, thin-walled, uninucleate vesicle in the epidermal 
cell. 
The nature of the filament, whether hyaline or brown, thick or thin, 
appears to be a character specific to the fungus concerned, and is not generally, 
as suggested by Maire, correlated with the thickness of the cuticle to be 
traversed. 
Certain species penetrate through the epidermis, through sclerenchyma 
cells, if these are present, into the first chlorophyll-containing cells of the 
mesophyll ; but the form of all the haustoria examined was in general the 
same, consisting of a penetrating filament and a delicate uninucleate vesicle. 
The differences in different species consist in the length and character of the 
penetrating filament. 
The character of the penetrating filament is of diagnostic value ; and 
may, in some cases, be employed as a determining factor when there is any 
question of the identity of two species. 
The haustoria cause a considerable disorganisation of the cells into which 
they penetrate, and the mycelium completely blocks many of the stomata. 
The fungi of the genus Meliola must therefore have a prejudicial effect on 
plants which are heavily infected, especially on the young seedling trees 
which seem to be generally susceptible. 
Literature Cited. 
1. BoRNET. — " Organisation des Meliola," 'Ann. Sc. Nat. Bot.,' xvi, 1891. 
2. Gaillard. — ' Monographie du genre Meliola,' Paris, 1892. 
3. Maire. — '•' Les Sucoirs des Meliola et des Asterina," 'Ann. Myc./ 6 (1908), 
pp. 124-128. 
4. DoiDGE. — "South African Perisporiales," 'Trans. Roy. Soc. South Africa/ v. 
Part 6, 1917. 
5. GrUEGUEN. — " Emploi du Sudan III comme colorant mycologique, seul, ou combine 
au bleu coton et a I'iode," ' Bull. Soc. Myc. France,' xxii, p. 224 (1906). 
6. Harper. — " Ueber das Verhalten der Kerne bei der Fruchtentwickelung einiger 
Ascomyceten," 'Pringsh. Jahrb. fiir wiss. Bot.,' xxix, pp. 655-685, 1896. 
