LEAF FUNGI 169 



The hyphopodki are minute outgrowths of the hyphae, 

 peculiar to these families, which occur at regular inter- 

 vals on the hyphae, and w^hich are regarded as unde- 

 veloped reproductive bodies or undeveloped sterile 

 ])i'anches (Fig. 2, A and B). 



The reproductive bodies are called perithecia when they 

 are spherical and tJujriothecia when they are flattened; 

 they enclose small sac-like bodies the asci, each of which 

 contains 2-8 spores. Each spore (Fig. 2 D) is capable 

 of producing a small plant. Sterile erect branches are 

 referred to as setae (Fig. 2 C). 



With this preliminary explanation, we can proceed to 

 note the characteristics of the two families. Fig. 3 is a 

 photograph of a microscopic preparation of one of the 

 Perisporiaceae (Meliola glahra). It consists of brown 

 radiating hyphae, bearing hyphopodia at regular inter- 

 vals; these are of two kinds, the most numerous are two 

 celled, and rounded, they are known as capitate hyphopo- 

 dia (see also Fig. 2 A), and are considered to be unde- 

 veloped perithecia; the other kind are less numerous, 

 they consist of a single cell and taper to a short neck, 

 they are almost bottle-shaped (Fig. 2 B), and represent 

 undeveloped branches. 



There are no setae in this particular species. In the 

 centre of the spot there are several spherical perithecia, 

 and scattered about there are a number of 5-celled brown 

 spores, most of w^hich are germinating. 



The next figure (4) shows one of the family Micro- 

 thyriaceae : the mycelium is similar to that in the pre- 

 vious figure, but is more slender, and there is only one 

 kind of hyplioi)odium. The chief difference is in the form 

 of the reproductive bodies, which in this group are flat- 

 tened -hemispherical and formed of hyphae radiating from 

 a central point. They are termed thyriothecia. 



The characters, which are of importance in determin- 

 ing the genus to which a fungus belongs, are best ex- 

 pressed in the form of a key. I append a key to the more 

 important genera of the two families, which may be of 

 use to collectors : — 



