COFFEE-DISEASE IN SOUTH AMERICA. 465 



decessors. It must be remembered that the perithecia are never 

 numerous on the spots, and that at least half the discoloured spots 

 are wholly without them. The spots are present, but there are 

 no external evidences of fungi; and in some of these naked 

 spots which were examined internally I failed to trace any 

 mycelium. 



There is, however, still another feature in connexion with 

 these discoloured spots, that upon some of them, sometimes on 

 the upper and sometimes on the under surface, another and very 

 different kind of fungus flourishes. A pocket-lens will be suffi- 

 cient to detect on some of the spots small, erect, slender, yellow 

 threads with a globose head, five or six of them upon one dis- 

 coloured spot. Sometimes they will be found on the same spots 

 as the perithecia of the Sphcerella, and sometimes on spots in 

 which no perithecia can be detected. This Stilbum, which has 

 been named Stilbum flavidum* , has, like all other species, a com- 

 pound stem formed of a bundle of slender filaments, parallel to 

 each other, fused into a common stem, terminated by a globose 

 head, composed of the free ends of the component filaments, sub- 

 divided and terminated by minute subglobose spores, scarce '0015 

 millim. in diameter. This corresponds very closely with the de- 

 scription of the parasite as described by Professor Saenz, who 

 indicated " the circular or elliptical blotches of an ochreish-yellow 

 colour " and the "hard knots in the centre," which are the peri- 

 thecia of the Sphcerella, and the " small fungi of a yellow colour, 

 formed of a very delicate pedicle crowned by a small sheaf of 

 fibres, in which are an abundance of oval corpuscles." The only 

 difference appears to be that his measurement of the corpuscles 

 is about double that of mine, his being '003 millim., and my own 

 '0015 millim. for the spores of the Stilbum, a discrepancy not so 

 very extraordinary when the minute size of the bodies is taken into 

 account. 



The Commissioner of Agriculture at Bogota also undoubtedly 

 saw the same fungus, although his description is less exact and 

 accurate. Whether there is any foundation for the belief that 

 this little fungus is phosphorescent or emits an odour of phos- 

 phorus, cannot be affirmed, as he evidently mentions it with 

 some reservation. 



I have now demonstrated that the coloured spots may be 

 without any visible fungus upon them, and exhibit no trace of 

 * ' Grevillea,' ii. p. 11 (1880). 



