THE DISEASES OF THE SUGAR-CANE. 311 



able to distinguish the work of different parasites than in 

 the days of the " Blast". It does not seem, with all their 

 variety, that the diseases are more fatal nowadays. In this, 

 and in other respects, the cane epidemics of former days 

 remind one of the "plagues" of the Middle Ages. The 

 list of diseases to which the human frame is liable has been 

 vastly lengthened by the advance of medical science ; but 

 the means of fighting them has increased in a much greater 

 degree. The net result is healthier lives : may it be so in 

 the cane-fields too ! 



It has been said that a healthy human stomach is cholera- 

 proof: and a parallel may again be drawn with healthy cane 

 plants. A cursory examination of the latter is sufficient to 

 convince one that most, if not all, the diseases of past years 

 are present in a subdued form. The Aphis of the " Blast," 

 the " vSugar-Ant " of Barbados, the " Blackblight " and 

 Cuckoospit," even the dreaded " Rust" of Queensland are 

 all at the present moment widely distributed in the cane- 

 fields, but not injuriously so. 



On the other hand, just as new and obscure maladies 

 appear at intervals among human beings, there are evidences 

 of incipient parasitism among the cane pests. Saprophytic 

 forms appear to have become parasitic, and feeble parasites 

 have been changed into dangerous and destructive pests. 

 The "Rind-fungus" of the West Indies appears to afford 

 an example of this. Trichosphaeria Sacchari is regarded as 

 an undoubted and dangerous parasite in these islands.^ 

 Although usually requiring a " bore-hole " for its starting 

 point, evidence from Barbados appears to denote that this 

 is not always necessary ; for, as crop proceeds, an in- 

 creasing number of diseased plants are met with which, 

 after the most careful search, reveal no traces of borers.^ 

 In Queensland the Trichosphaeria has been proved by 

 inoculation experiments to be an undoubted parasite,^ 

 although it is far more abundant as a saprophyte upon the 

 dead pieces of stems and leaves. In Mauritius it is 

 doubtful whether the fungus is parasitic, although fairly 



^ Massee, etc. - Barbados Experimental Station Reports. ^ CobI) (3). 



