144 Sy<^te.matic Arrangement. 



CHAPTEE XXIII. 



Systematic Arraxgemext and Technical Descriptions. 



Considering the wide distribution of the smuts and the numerous host- 

 plants on which they grow, there is every reason to believe that there are 

 still a number to be discovered in Australia. Apart from those which attack 

 the cereals and which have consequently been brought prominently under 

 notice, they have not attracted much attention, and it is only at particular 

 seasons of the year that they are visible to the ordinary observer. Hence, 

 while the following descriptions include all those which are at present known 

 general conclusions cannot safely be drawn as to their distribution. Only 

 the eastern portion of the Continent has received the attention of collectors, 

 and the prevalence of smuts in the western portion is practically unknown. 

 Much closer observation and extensive search is required before anything 

 approaching a complete survey can be given, and if it be asked why then 

 attempt it at all, I would reply that a clear and definite account of the forms 

 already found will pave the way for further additions and discoveries. In 

 some cases, too, there are only solitary specimens available, and the procuring 

 of material at different stages and from various localities is desirable. The 

 ten Australian genera have already been shown in their relation to genera 

 in other parts of the world, and the 68 species have been described and 

 illustrated in such a way that their identity can always be traced. It will be 

 observed in the description of the species that I have used what is called 

 the anatomical method, that is to say, the deep-seated characters as well as 

 the more superficial ones, wherever possible. 



Order — Ustilaginales. 



Fungi parasitic in the tissues mainly of herbaceous flowering plants and 

 developing a mycelium, local or widely extended, consisting of delicate, 

 hyaline, septate, branching filaments, which often disappear partially or 

 entirely at maturity through gelatinization and deliquescence. 



Fertile mycelium composed of compact masses giving rise to spores from 

 their internal contents, rarely forming conidia externally. 



Sori evident, forming powdery or agglutinated masses of spores on definite 

 portions of the host, sometimes permanently imbedded in the tissues. 



Spores generally dark coloured, single, in pairs, or in spore-balls, which 

 may be composed partly of sterile cells. 



Grermination by a promycelium, usually producing lateral or terminal 

 conidia, which may either germinate in turn and directly penetrate the 

 host-plant or reproduce themselves by budding in a yeast-like manner, and 

 then germinating. 



The Ustilaginales are typically parasitic fungi, which show the most 

 perfect adaptation to their host-plants, and produce their spores asexually 

 from single divisions or cells of the mycelium. But since parasites are 

 assumed to have been derived from saprophytes, they still retain the sapro- 

 phytic habit, and this is clearly seen, even in such pronounced parasites as 

 the smuts. 



When the spores escape from the host-plant, they can germinate readily 

 in water, and produce a short germinal tube bearing single conidia, but in 

 nutritive solutions they go further than this, and continue to produce 

 reproductive bodies as "long as the nutriment lasts. The spore germinates 



