33Q DISEASES OF CULTIVATED PLANTS 



disease, C. arabica, planted at the same time, has been 

 entirely destroyed.' 



Uredospore stage. Uredospores forming small groups 

 seated on yellow spots on under surface of leaf, subreniform, 

 triangular in section, free convex surface warted, margined by 

 longer, spinulose warts, the two lateral surfaces, in contact 

 with adjoining spores, smooth, orange, 30-40X28-30 /*, 

 pedicel slender, short. 



Teleutospore stage. Teleutospores occupying the centre 

 of the heads of uredospores, broadly depressed ovate, 

 umbonate, smooth, contents orange, averaging 30 x 25 /x. 



Hemileia Canthii (Berk, and Broome) is a synonym of this 

 species. 



But little appears to have been attempted in the way of 

 spraying as a preventive against an epidemic. In places 

 where the nature of the ground, and other circumstances 

 permit, probably spraying with Bordeaux mixture might be of 

 service. The strength of the mixture would have to be 

 determined on the spot. Judging from analogy, this method 

 should be successful, as the uredospore condition is the one 

 that spreads the epidemic, and this form is produced on the 

 coffee plant. 



All diseased leaves should be burned and not allowed to 

 lie about, as the teleutospore or resting-spore stage is also 

 developed on the leaves, and infection might follow. 



Hennings, Zeit. Trap. Landw. Trqpenpfl., No. 8, 1897, 

 p. 192. 



Massee, Kew Bulletin, No. 2, 1906. 



Ward, Quart. Journ. Micr. Sci., N.S., 22 (r8S2). 



Hemileia Woodii (Kalchbr. and Cooke). This species 



forms yellow spots on leaves of Vangueria infausta, V. lali- 



foiia, I', euonymoides, V. madagascarensis, and on Cojffea Ibo 



in Africa. On various species of Gardenia in Java, and on 



Gardenia edulis in Queensland. 



Uredospores forming powdery orange patches, broadly 

 elliptical or subglobose, warted, about 30 /x diam. Teleuto- 

 spores occupying the centre of the uredospore mass, almost 

 colourless, broadly ovate, umbonate, smooth, about 35 /* 

 diam. The head of spores is surrounded by curved, smooth 

 paraphyses. 



Massee, Keiv Bulletin, No. 2, 1906. 



Hemileia americana (Massee). Specimens of the orchid 



