234 FUNGOID PESTS OF CULTIVATED PLANTS. 



The pustules of the teleutospores are also minute, blackish, and 

 scattered over the leaves and the leaf sheaths. Teleutospores, mostly one- 

 celled, and irregular in form (24-30 x 16-1 8/<i), sometimes two-celled, club- 

 shaped, blunt at the apex, or narrowed (40-48^ long) basal cell narrowed 

 (16-18/i broad), the upper cell (19-24/1 broad). 



Mass. PL Dis. pp. 250, 414. 



RED MOULD OF BARLEY. 

 Fusarium Hordei (W. G. S.), PL XXII. fig. 11. 



This gelatinous mould, described by Worthington Smith, he considers 

 more injurious to Barley, and more common, than is generally supposed. 

 Possibly it is the same as the Fusarium graminearum of the Journal of 

 the Royal Microscopical Society (June 1883, p. 321). The fungus chiefly 

 attacks Barley of poor quality, and ill-conditioned crops and ears. 



The mycelium is rose-coloured or crimson, effused, forming a thick 

 gelatinous stratum. The threads are septate, and somewhat torulose. 

 The conidia are spindle-shaped, narrowed to each end, with from one to 

 three septa, slightly curved (30 x4/*) and rose-coloured or red. Some- 

 times these conidia will germinate from any one of the cells whilst still 

 attached to the threads. At other times they will separate at the joints, 

 and each cell assume a rounded form, becoming, in fact, a globose spore 

 (5fi diam.). 



Said to be met with in Europe, South Africa, and the United States. 



Smith, Field Crops, p. 210, figs. 93, 94 ; Sacc. Syll. xi. 4165 ; Mass. 

 PL Dis. p. 331. 



Another species, Fusarium Lolii (W. G. S.), occurs on Lolium 

 perenne. 



Sacc. Syll. xi. 4166 ; Smith, Field Crops, p. 213. 



LOOSE SMUT OF OATS. 

 Ustilago Avence (Jens.), PL XXII. fig. 12. 



This is the old form of Ustilago segetum on Oats, and is found convert- 

 ing the grains into a loos^e sooty powder. 



The mass of spores is rather lax, and dark brown. The spores them- 

 selves are globose, or shortly ovoid (6-8^ diam., or 7-9x6-7^), very 

 delicately warted or punctate. In germination the promycelium is 

 pointed, producing at the joints oblong sporidiola. 



It will be seen how much reliance is placed by modern authors on the 

 peculiarities of the promycelium in germination. 



This form is recorded for Europe and North America. 



Recent experiments have proved that sprinkling the seed grain with a 

 1 per cent, solution of either lysol or formalin entirely prevents the smut. 



Sacc. Syll. ix. 1161 ; Smith, Field Crops, p. 255, figs. 117-119 ; Mass. 

 PL Dis. p. 210, fig. 50 ; Journ. E.H.S. xxvi. 1902, p. 728, fig. 304. 



