464 ME. M. C. COOKE ON THE 



being greatest in plantations where the trees are planted rather 

 close. The fungus has also attacked the shade-trees, especially 

 the Gruamos {Inga sp.)." 



Other communications which I have received, accompanied by 

 specimens, demonstrate that the same disease is spreading widely 

 through the coffee-districts of Costa Rica and other parts of 

 Central America, New Granada, and Venezuela, and causing con- 

 siderable alarm. 



The leaves and unripe berries are marked by distinct pale spots, 

 nearly orbicular, with a regular well-defined outline, and in the 

 leaves quite perfect on both surfaces, from about a quarter to 

 nearly half an inch in diameter, from two or three to five or six or 

 more spots on the same leaf. These spots are often quite smooth, 

 uniform in colour, and without any external evidence of the pre- 

 sence of a fungus. In these instances they seem as if they might 

 as well have originated with an insect as with a fungus. Others 

 of these pale spots are occupied by a few minute dark-brown 

 perithecia, so minute as not to exceed the puncture of a pin. These 

 perithecia, seated on pale orbicular spots, constitute the Depazea 

 maculosa of Berkeley ; but as I have found in all of them which 

 I have examined perfect asci and sporidia, they were named and 

 described as Sphcerella cqffeicola*. At that time I had not seen 

 the specimens which Berkeley determined as Depazea maculosa ; 

 but as he found no asci, and characterized it as a Septoria, the 

 Sphcerella may be treated as a distinct fungus, although, in my 

 own opinion, it is only the perfect or ascigerous condition of 

 the same parasite. 



The question would arise at once as to the general character of 

 Septoria and also of Sphcerella, and whether they are likely to be 

 productive of such a disease as that of the South-American coffee. 

 There are no very distinct records of species destructive in this 

 manner and to this extent ; but there is, on the other hand, no 

 reason why either Septoria or Sphcerella may not be destructive. 

 This may be affirmed more strongly of Sphcerella ; since within 

 the past two years Sphcerella Taxi has undoubtedly proved very 

 destructive to yew-trees in Cornwall ; and as for Septoria, some 

 species have, to a limited extent, appeared as a destructive pest. 

 Under any circumstances, if this really proves to be the cause 

 and not a consequence of the coffee-disease in South America, it 

 has the merit of being more truly devastating than any of its pre- 

 * ' Grevillea,' ix. p. 10 (1880). 



