FUNGOID PESTS OF CULTIVATED PLANTS. 237 



Maize Blight, 



caused by a black mould, Helminthosporium inconspicuum (C. & E.), 

 is often destructive to the foliage of Maize in South Europe, Queensland, 

 and the United States. 



Mass. PL Dis. p. 313, fig. 84. 



Red Gelatinous Mould. 

 Fusarium heterosporum (Xees), PI. XXIII. fig. 17. 



Some authors consider this a distinct species, whilst others contend 

 that Fusarium Hordei and Fusarium Lolii are only varieties. Let each 

 be persuaded in his own mind. This species occurs on the fruits and 

 glumes of Lolium perenne, on Rye, and on several grasses. 



The clusters are reddish, somewhat tremelloid exudations, which 

 consist of the mycelium, and the short conidiophores with their conidia. 

 The latter are at first almost globose, then they become fusiform 

 (30-85/*. long) and from three to five septate. This parasite is often 

 found in company with ergot. 



It has been recognised in Germany, Italy, Cuba, Argentina, and North 

 America. 



Sacc. Syll. iv. 3343 ; Mass. PL Dis. p. 331, fig. 91 ; Cooke, Hdbk. 

 No. 1G7G. 



Timothy Grass Rust. 



Puccinia Phlei-pratensis (Eriks.). 



This is a recently constituted species found upon the leaves and 

 sheaths of Phleum pratense, but which is believed to have been con- 

 founded previously with some other species. 



The pustules are elongated and confluent, erumpent, and dark brown. 

 Teleutospores fusoid-clavate, slightly constructed in the middle, and 

 either rounded or acute at the apex, of a chestnut-brown colour 

 (38-52 x 14-16/0- 



The uredospores have also been observed, and rather imperfectly 

 described as oblong pear-shaped, rough externally, and yellow 

 (18-27x1 5-1 9 A <). 



It has been recorded for Sweden and Denmark. 



Sacc. Syll. xi. 1161 ; Mass. PL Dis. pp. 249, 414. 



Grass Mildew. 

 Erysiphe graminis (DC), PI. XXIII. fig. 18. 



This mildew is familiar on the leaves of most grasses, and commences 

 with the patches of thin creeping white mycelium, common to all these 

 kinds of mildew, the Oidium stage, in which the erect branches bear chains 

 of colourless elliptical conidia. Before the advanced condition was known 

 this condition was called Oidium monilioides (PI. XXIII. fig. 19). 



Afterwards the globose receptacles appear dotted over the mycelium, 

 like little points. The appendages which usually surround the receptacles 



