43 . . 

 side rows are more apt to be open dtiring fertilization than those of the 

 middle rows. Among the two-rowed barley, the variety nutans very often 

 has ergot and the variety erectum . on the contrary, very seldom. This 

 condition apparently bears some relation, according to Henning, to the 

 fact that open flowers in six-rowed barley, as well as in the variety 

 erectum of t^ro-rowed barley, occur comparatively seldom. He also 

 einphasised the fact that infection with ergot presupposes open flowers. 

 These observations of Henning. were confirmed and extended by Tschermalor. 

 The glumes of the two, four, and six-rowed huHess barley varieties are 

 relatively wide open, hence their inclination to outside pollination and 

 ergot infection. Hannchen barley, which has more open flowers than other 

 varieties, is also more susceptible to ergot (158) Rapidly flowering 

 barley often has open flowers and is., therefore, more exposed to infection 

 (274) 



TM glumes of wild rye remain open for longer time because 

 the anthers do not discharge their pollen all at once, but the latter are 

 set free very gradually and only after a long drying out. On account of 

 this the wild rye depends more upon an outside pollination than does the 

 cultivated rye. With this mode of flowering, it is more lilcely to remain 

 sterile and therefore more exposed to the spores of ergot. This is also 

 true for the F-, generation of the perennial hybrid Secale montana x Secale 

 cereale, as well as for the greater part of the segregation products of 

 the latter generation. 



lUie spikelets of late rye remain open longer and they also 

 lose the elasticity which enables them to draw bade the glumes, the latter 

 remaining in this position during dry and hot weather even after ferti- 

 lization has taken place, and regaining their elasticily only after the 



y 



coming of rain. ;|fe^while the flowers may become infected. 



