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RESEARCHES ON FUNGI 



Fig. 114.- — Tilletia tritici. The development and mode of discharge of so-called 

 secondary conidia (the authors' primary and secondary basidiospores). A : the 

 chlamydospore c has germinated on a substratum of malt-agar sub and has 

 produced a promycelium (basidium-body) consisting of three basal cells b, 

 which have lost their protoplasmic contents and are dead, and of an apical 

 cell a, which is lined with cytoplasm and is still living. The promycelium may 

 be supposed to have been crowned by twelve long and slender primary conidia 

 (primary sterigmata) p p which have conjugated in pairs ; but, for the sake of 

 clarity, only the front three pairs have been represented. The protoplasm 

 migrated from the promycelium into the primary conidia and, during this 

 migration, the promycelium developed three septa in succession from its base 

 to its apex. The right and left pairs of primary conidia have each produced a 

 short sterigma (secondary sterigma) st and a secondary conidium (primary 

 basidiospore) s. The protoplasm in the pair of primary conidia on the right 

 migrated into the secondary conidium s and, during the migration, the primary 

 conidia became exhausted and septate. In the pair of primary conidia on the 

 left the migration of the protoplasm into the secondary conidium is nearly, 

 but not quite, completed. The middle pair of primary conidia has only recently 

 conjugated and has not yet produced a sterigma and a secondary conidium. 

 Hence it is still full of protoplasm and not yet septate. The secondary conidia 

 (primary basidiospores) s s, within about an hour, would be shot from their 

 sterigmata by the drop-excretion method illustrated in D. Magnification, 660. 

 B : a surface view of a pair of primary conidia (primary sterigmata) p which 

 has fallen on to the nutrient substratum (malt-agar) and has developed directly 

 into a branched and somewhat coiled mycelium m. The mycelium, at intervals, 



