FUNGOID PESTS OF CULTIVATED PLANTS. 23 3 



are more or less elongated, pallid, and often with a narrow fuscous margin, 

 limited by the veins. Perithecia covered, scarcely visible, except under a 

 lens. Sporules straight or slightly curved, minutely nucleate (55-75 



Known also in France, Italy, Austria, and North America. 

 Sacc. Syll. iii. 3068 ; Cooke, Hdbk. No. 1315. 



BARLEY SMUT. 

 Ustilago Hordei (Kell.), PL XXII. fig. 9. 



This is part of the original Ustilago segetum or Ustilago carbo, and 

 appears to be confined to the ovaries of Barley, which are converted into 

 a rather hard, persistent mass of spores. 



The mass of spores is black and rather compact. The spores them- 

 selves are globose and obtusely angular (6| X 1\ p diam.), smooth, and 

 dark brown. In germination the promycelium becomes three to four 

 jointed, producing a sporidiolum at each joint. 



Recorded for Europe and North America, but it is uncertain to what 

 extent it is found in Britain, as the common and prevalent form is loose 

 and powdery. 



Steeping the seed in half per cent, copper solution is recommended as 

 preventing the disease. 



Sacc.Syll.iTL.-HQ5', Smith, Field Crops, p. 117 ; .Mass. PZ. Dw. p. 214, 

 fig. 51. 



NAKED BARLEY SMUT. 

 Ustilago nuda (Jens.), PL XXII. fig. 10. 



This is one of two species of smut which are now believed to infest the 

 ovaries of Barley. It is in the United States that their differences have 

 been more specially investigated. 



The mass of spores is olive-brown, loose, and soon free. The spores 

 themselves are ovoid, ellipsoid, or sub-globose (5-7x5-6^), somewhat 

 olive. In germination the promycelium is sparingly branched, with the 

 apices sometimes inflated. 



Recorded for Europe, North America, and Japan. 



Very resistent to fungicides. Differs from the other species in the 

 spore masses being powdery and easily dispersed. 



Sacc. Syll. ix. 1164 ; Mass. PL Dis. pp. 215, 401. 



BARLEY RUST. 



Puccinia simplex (Eriks.). 



This supposed species occurs on the leaves of Barley, but the cluster- 

 cup stage is unknown, and hitherto unsuggested. 



The uredo pustules are very minute, and are sparingly scattered on 

 the upper sides of the leaves and of a pale yellow colour. The uredo- 

 spores are globose, or broadly elliptical, externally rough (19-22 diam. or 

 22-27 x 15-19yu), pale and yellowish. 



