112 



(PL XVIII). It is so brittle that by gently tapping the cover-glass over 

 conidia the outer dark wall of every one of them may be broken in frag- 

 ments, much as a peanut is broken if stepped upon. This character 

 is common to H. Nos. 1, 3, 5, 13-16, etc., as well as to H. HO. 2, _and many 

 other species, though in some the wall is less brittle than in others. The 

 conidial wall that is left after the solution of the endosporium by sulfuric 

 acid is entirely without sign of septation, but shows the apical spot clearly 

 differentiated as a thin pale region. 



FIG. 10. Variation in conidial shape and septa- 

 tion of H. No. 1, and showing also the dark spot, 

 stipe, at basal end, and the pale apical spot. 



Conidial contents. Within the thin colored wall are the protoplasts, 

 usually vseveral in number (Fig. 11), and between the protoplasts and the 

 outer wall is a thick hyaline layer of substance that is somewhat soft, usually 

 appearing almost gelatinous (PL XVIII). This hyaline soft layer represents 

 morphologically, I believe, a second cell-wall, the endosporium of de Bary 

 (9). I shall so speak of it. That this wall is soft is shown by the way the 

 conidial contents issue from the end of a cracked conidium under pressure 



