TILLETIA TRITICI 



243 



exhibit abnormalities in connexion with their discharge, 

 normalities are doubt- 

 less due to the lack of 

 ventilation of the air 

 of the chambers, and 

 it seems probable that 

 one of the ventila- 

 tion factors adversely 

 affecting spore - dis - 

 charge is saturation of 

 the air with water- 

 vapour. The abnor- 

 malities about to be 

 described were all 

 observed in closed 

 glass - ring chambers 

 with the low power 

 of the microscope 

 (magnification, 160). 



The semi-diagram- 

 matic Fig. 118 shows 

 an H -shaped pair of 

 primary sterigmata, st, 

 which has sent out a 

 hypha which on malt- 

 agar has produced a 

 winding and branched 

 mycelium m. At in- 

 tervals along the hy- 

 phae of the mycelium 

 have been developed 

 aerially and success- 

 ively a number of short 

 sterigmata each of 

 which bears a single 



These ab- 



Fig. 118. — Tilletia tritici. Abnormalities in the dis- 

 charge of secondary basidiospores (Brefeld's 

 secondary conidia) represented semi-diagramma- 

 tically. An H -shaped pair of primary sterigmata 

 (primary conidia) st has germinated on malt-agar 

 and has" produced a winding and branched myce- 

 lium m; a, asickle-shaped basidiospore fullygrown, 

 borne on the end of a short sterigma ; b, another 

 basidiospore which, within the last 20 seconds, 

 has excreted a drop of liquid of normal size at its 

 hilum ; c, the drop has become abnormally large 

 and has run up on to the basidiospore ; d, the 

 drop has become so large that it has enveloped 

 and hidden the basidiospore ; e, a basidiospore, 

 covered by an abnormally large drop, which has 

 not been discharged but has germinated in situ, 

 the germ-tube having been emitted from its 

 apex ; /, a basidiospore which did not excrete 

 a drop of liquid, was not discharged, and has 

 emitted a germ-tube at its apex ; g, an undis- 

 charged basidiospore which has emitted a germ- 

 tube at its base ; h, a basidiospore which did not 

 excrete a drop of liquid, was not discharged and, 

 even after several hours, has not germinated. 

 Magnification, about 330. 



sickle-shaped second- 

 ary basidiospore. At a is shown a basidiospore which is just fully 



