298 SCIEXCE PROGRESS. 



comes necessary for the machinery to be worked night and 

 day to prevent serious loss. The cause of this decrease is 

 that the canes are infested by animal and vegetable para- 

 sites which increase enormously as the canes ripen. It be- 

 comes literally a race between the mill and the cane pests 

 as to which shall appropriate the spoils of the fields. 

 Disease is spread abroad in the estates, changing the de- 

 licious juicy canes into vinous and putrid masses. Let 

 us glance at the state of the plantations in different parts of 

 the Tropics. 



3. Java, one of the largest and most successful of cane- 

 o;rowinof countries, is saturated from one end to the other 

 with Sere/i, a disease which, after years of close study, has 

 much in it still to puzzle the plant-pathologist. As in many 

 other maladies, there are all degrees between perfect health 

 and pronounced disease, and it is difficult to mention any 

 one characteristic symptom. In severe cases, instead of 

 the normal formation of long healthy joints, the plants be- 

 come stunted, the canes are arrested in their growth and 

 remain short, while the lateral buds, usually flat and 

 " sleeping," swell and grow out. A bush-form is thus 

 arrived at, more or less resembling that of '* sereh "" the 

 common lemon-grass {^Andropogon SchoenaiitJms)} The 

 root-system is poorly developed and diseased at the tips ; 

 and what food materials find their way into the stem are 

 diverted from the cane to the bursting lateral buds. In 

 such a plant the fibrovascular bundles are seen to be red in 

 colour, especially at the junction of leafsheath and node ; ' 

 the large vessels are filled with gum which contains im- 

 mense numbers of bacteria. Obviously this must interfere 

 with the water supply ; but it seems probable that the 

 bacteria are mere accompaniments of the disease. 



It is difficult to form an idea as to the actual loss infiicted 

 on the island by sereh. One writer has calculated that in 

 1889 the diminution of crops in Mid Java alone represented 

 a loss of two and a half to five million gulden (^200,000 

 to ^400,cxD0?).^ A more recent estimate, based upon 



^ Krliger (i) p. 126. -Went (i) p- 470. ^May. 



