KEY. E. ABBAY OX HEMILEIA YASTATHIX. 175 



deficiency in the whole island has been estimated by some as at lea st 

 £2,000,000. Since the " disease" made its appearance in 18G9, 

 the enterprise has suffered to the extent of from £12,000,000 

 to £1.5,000,000 in crops alone ; yet I believe there is not a single 

 recorded instance of a tree having been killed by the pest ; besides 

 which it must be remembered that the seasons have been excep- 

 tionally unfavourable. The effect is simply to deprive the tree 

 of its leaves, and slowly and surely to weaken it if the strength 

 of the plant is not continually renewed by means of manure. 



Absolutely nothing is known as to the origin of the pest beyond 

 what has been already stated. It is found on no other plant 

 except the coffee-tree, nor until some sixteen or eighteen months 

 ago, when it appeared in Sumatra, in any other country except 

 Ceylon and Southern India. From what follows in these pages as 

 to the character of the " disease," it will, I am afraid, appear to be 

 almost impossible that Java can escape the importation of it from 

 Sumatra ; but it is perhaps a matter of doubt whether the condi- 

 tions of that climate are so favourable to its growth and develop- 

 ment as those of Ceylon seem to be. 



If such be the case, the production of coffee in the East, if not 

 also in Brazil, may at no distant date be much restricted, unless, as 

 is possible, some method should be discovered of successfully con- 

 tending with the pest. The vitality of the spores of the fungus 

 forming the " disease " is somewhat remarkable, and apparently 

 places no limit to the distance to" which they may be conveyed, 

 or to the period during which they will retain their power of ger- 

 mination. The writer has at the present time (April 1878) spores 

 growing readily which were sent from Sumatra to Ceylon sixteen 

 months ago, and afterwards transmitted in the middle of winter 

 to England. 



General Description of the Coffee- Fungus. — At a very early date 

 in its history Mr. Thwaites, F.E.S., Director of the Botanical 

 Gardens at Peradeniya, in Ceylon, discovered that the pest was a 

 fungus, with certain points of resemblance to the Uredinea), whose 

 mycelium permeated the tissues and fed on the juices of the leaf. 

 Messrs. Berkeley and Broome described the fruit of the fungus 

 in the ' Gardeners' Chronicle ' for 18G9, p. 1157 ; but the writer 

 believes that no serious attempt has hitherto been made to grow 

 the plant and ascertain its true character. 



The first indication of the " disease " is a palish discoloration 



i»2 



