192 



pertv of coiipiflerable age is free from the various bark and root 

 diseases so prevalent throughout the East. We believe that on most 

 plantations there are plenty of affected specimens to be found if 

 the staff is free to search for them. We have generally found that 

 the keener the managers and assistants are the larger the number 

 of cases reported in the usual monthly statement." 



It is a matter for considcratioii as to ■whether the term 

 " Scares " should be applied to the recording of these diseases- 

 which are obviously always with us but only occasionally reported, 

 according to the opportunity the scientist has to investigate them 

 or as they assume undue prominence. The}' may probably provide 

 a " Scare " for the outside man who is nervous and over anxious 

 about his investment but they sliould hardly be considered in that 

 light by competent experienced managers for with the assistance of 

 these same scientists who record these diseases, they should feel 

 quite capable of dealing with them and holding them in check. 



T. F. CiiTPr. 



Tuba-Root (Derris elliptica). 



As AN IXSKCTICIDK. 



Eeaders of George Maxwell's "In Malay Forests" will re- 

 collect the graphic account of a fishing expedition where the Malays 

 used the root of the Tiiba-plant as fish poison. 



Many plants exist in the Tropics, and notaljly in India, which 

 can be put to the same purpose of killing fish, and Watts' Diction- 

 ary gives a fairly long list of them. Throughout the Malay Archi- 

 pelago Tulja-root appears to be the poison most in use, and a very 

 effective one it is in the hands of expert natives. 



The interesting question arises whether the toxic ])ro])erties of 

 this root are also effectual for the destruction of insect life; for, if 

 such were the case, its application to agriculture is naturally all 

 indicated. 



The Chinese ap])ear to have solved the question to their satis- 

 faction, for we know that they employ tuba extensively for the 

 protection of their crops against injurious insects. In Sarawak, 

 the Chinese pepper planters always have, or had (for the writer's 

 visit dates far back) a few bushes of tul)a growing alongside their 

 vines.* 



Beyon(] that knowledge, however, the enquiry suggests itself 

 whether the macerated tuba-root, as used by the Cliinese, acts as 

 a stomach-poison to chewing insects, when taken with their food, 

 as it does in the case of grasshoppers and beetles, or as a contact 

 poison for insects which obtain their food by sucking as bugs and 

 plant-lice generally do, or whether its toxicity is effective both as 

 a contact ami a stomach poison. 



* Tuba-root is now largely grown in Singapore. 



