was very prevalent in the West Indies, where it almost 

 paralysed the sugar industry for a time ; in addition to 

 occurring in the West Indies it has been reported from 

 India, Java, Mauritius and Queensland. 



The fungus gains access to the interior of the cane at a 

 wounded surface, such as the broken end of a lateral shoot 

 or leaf base, but more especially through the wounds 

 made by the moth- borer insect {Diatraa saccharalis) and 

 sometimes also the shot-borer (Xylebonts perforans). In 

 the interior of the cane the fungus follows the course of the 

 vascular bundles, and when the disease is in its incipient 

 stages the pulp of the cane shows a number of bright-red 

 longitudinal streaks. Later on, the fungus spreads to the 

 tissue separating the vascular bundles and the whole of the 

 pulp becomes much reddened. Finally, the cane dies and 

 decays. 



Black curved tendrils make their appearance on the 

 surface of the diseased cane, oozing out from conceptacles 

 situated below the epidermis and consisting of unicellular, 

 pale-brown conidia. This is known as the Melanconium 

 stage of the fungus. The conidia are for rapid repro- 

 duction and can reproduce the fungus without the 

 intervention of any of the other spore-forms. 



Later on, lining the cracks and crevices in decaying canes 

 an intensely black, velvety layer is produced consisting of 

 conidia of what is known as the macroconidial stage of the 

 fungus. A microconidial form also occurs and is similar 

 to the macroconidial form, developing from the same 

 hyphae, but owing its peculiarities probably to light, 

 exposure, etc. 



Finally, the ascigerous stage makes its appearance on the 

 dead or more or less decayed canes. 



The following measures have proved effective in checking 

 the disease : 



Careful collection and burning of all diseased canes which 

 yield, as a rule, but little juice. 



The use of cuttings for replanting which are free from 

 disease. 



The sterilisation of cuttings, or " cane plants " as they 

 are often called, by soaking in dilute Bordeaux mixture 

 before planting. 



The raising of resistant varieties of sugar cane. 



Diagnosis: Melanconium stage conidia produced in 

 perithecia formed under the epidermis, unicellular, pale 

 brown, cylindrical, straight or slightly curved, 14-15 by 

 35-4 microns. 



Macroconidial stage conidia produced in chains, origi- 



20 



