THE FUNGI 



231 



cavity, forming what is here called the columella (Fig. 

 96, E, c). The wall of the sporangium itself is not 



H G 



FIG. 96. Pilobolus. A, group of sporangiophores ; st, stalk; 

 r, reservoir ; s, sporangium. Magnified 5. B, hypha and 

 sporangiophore ; r, reservoir ; s, 6, sporangium. Magnified 

 15. C, sporangium in surface-view. Magnified 15. D, 

 sporangium (s) thrown off by bursting of reservoir (r} ; c, 

 columella. Magnified 15. E, reservoir (r) and sporangium 

 (s} seen in section ; b, thin part of wall ; m, mucilaginous 

 layer ; c, columella. F, the same, when the mucilage swells. 

 Magnified about 25. G and H, mycelial branches pre- 

 paring for conjugation. Magnified 120. J, later stage; 

 c, the conjugating cells. Magnified 120. K, after con- 

 jugation : z, the zygospore. Magnified 120. (After Zopf 

 and Van'Tieghem.) 



uniform throughout; the upper part is thickened and 

 cuticularised, and bristles with crystals of calcium 



