62 DISEASES, ETC. 



Page 433 — " Governor Nanclaren had for his successor 

 ■Colonel Don Pedro de la Moneda {1757). It ivas about this 

 time that an attempt was success/idly made to re-introduce the 

 Cacao jjlant. A new species {variety J. H. II.) the Cacao Foras- 

 tero, nihich being hardier, although not yielding the same fine 

 -quality, succeeded beyond expectation. It is this quality tohich is 

 •itill cultivated in our days'' 



Therefore it appears that a thirty-years interval elapsed 

 between the attack of the " blight " on the original Cacao, and 

 the re-introduction. The word " re-intrbduce," however, would 

 seem to imply that the first Cacao was introduced and not 

 indigenous to the Island but the force of evidence is now against 

 this view. 



The following account of this disease is condensed from 

 Bulletin of the "Botanical Department for July, 1899 : — The 

 disease is due to a parasitic fungus, known as Phytophthora 

 omnivora, a well known relative of that causing the potato 

 disease. This fungus is specially known in Europe by the attack 

 it makes upon young beech seedlings and many other plants 

 both in the open air and when grown under glass. 



It is nearly allied to a fungus called Pythium de Baryanum, 

 ■which causes a like destruction among seedling plants, generally 

 known as " damping off'." , Both fungi are essentially lovers of 

 moisture, and do but little destruction in dry weather. Phytoph- 

 thora reproduces itself in several different waysj stn'd its oospores 

 are capable of lying, dormant for as much as four years without 

 losing their vitality. (Hartig on Diseases of Trees, 1894, p. 45): — 



" Its gonidia (such as are formed on the surface of a Cacao 

 pod), are capable of being blown by the wind, or conveyed by 

 animals, insects or men. (Hartig.) " 



Tubeuf, in his work on the Diseases of Plants, 1897. p. 116, 

 says : — ■" Preventive measures against the whole group of fungi 

 to which Phytophthora belongs consists in the destruction by 

 burying or burning of diseased and dead parts of host plants, 

 which contain the hybernating oosptores, by change of crop on 

 infected fields, and by treatment with copper re-agents." 



Phylophdiora is said to cause an infectious disease. Once a 

 cacao pod is infected, the fungus permeates the pod by means of 

 the slender fungus filaments called hyphce and protrudhig through. 



