136 G. MASSEE AND THE FUNGUS FORAY. 



germinate and give origin to minute conidia which are distributed 

 by wind, and those that happen to be deposited on the young 

 leaves of a suitable host-plant germinate at once, enter the 

 tissues, and within a few days give origin to the conidial form of 

 reproduction once more. 



The function of resting-spores is to enable the fungus to tide 

 over that period during which the host on which it is parasitic is 

 not in a condition of active vegetation. 



Following the Peronosporese in the sequence of evolution, we 

 come to the enormous group of fungi, in the broader sense known 

 as the Ascomycetes; and throughout the assemblage conidial, and 

 what may be termed the sexual methods of reproduction are 

 present. However, in the Erysiphese, one of the oldest sections 

 of the Ascomycetes, the resting- spore phase is still the result of 

 a sexual act, whereas in the Sphseriacese and other sections, 

 although the fruit producing resting-spores is morphologically 

 similar to that of the Erysiphese, it is in reality asexual in 

 origin ; traces of the sexual organs are present in various sections, 

 but are functionally effete, and in others have become quite 

 rudimentary. 



Finally, in the most modern and highly differentiated group of 

 fungi, the Basidiomycetes, there is no vestige remaining of the 

 originally sexual mode of reproduction, the continuance of the 

 species depending entirely on the production of asexual conidia, 

 aided by various vegetative methods whose gradual evolution 

 progressed during the period of decadence of the sexual method of 

 reproduction. 



The last-mentioned ^roup, including the well-known and 

 universally distributed *' toadstools," mushrooms, pujffballs, etc., 

 illustrates the highest phase of evolution of the conidial form of 

 reproduction ; which, contrasted with the delicate mould-like form 

 first evolved, shows a remarkable amount of differentiation, being 

 always comparatively large, often gigantic, and sometimes woody 

 and perennial. 



Among vegetative modes of reproduction two forms are worthy 

 of special mention. Sclerotia are solid aggregations of mycelium 

 of variable size and form, depending on the species to which they 

 belong. In New South Wales, Victoria, and Queensland, certain 

 irregularly globose bodies varying in size from a cricket ball to 

 that of a child's head, dark bi'own externally, whitish and marbled 



