178 Journal of Agricultural Research voi. xvii. No. s 



The material available for the present study was secured in most cases 

 from various agricultural and botanical agencies through the Office of 

 Foreign Seed and Plant Introduction, United States Department of Agri- 

 culture. The following is a list of the material used and the sources from 

 which and through which it was secured: Powdered roots of a Derris 

 species, most likely Derris ellipiica Benth., from the open market where 

 it is sold as an insecticide; roots of D. ellipiica, called "tuba" or 

 "toeba" in the Dutch East Indies, from the 's Lands Plantentuin, 

 Buitenzorg, Java; stems of D. uliginosa Benth., from Mr. C. H. 

 Knowles, Suava, Fiji Islands; stems of D. koolgibbcrah ^ Baill., and of 

 D. oligosperma,^ from the director of the Botanical Gardens at Brisbane, 

 Queensland, Australia; roots of D. scandens Benth.; and stems and 

 roots of D. robusta Benth., from the director of the Botanical Survey 

 of Sibpur, Calcutta, India. 



HISTORICAL REVIEW 



The genus Derris, belonging to the family Papilionaceae, tribe Dal- 

 bergieae and subtribe Lonchoecarpinae, is practically native throughout 

 the Tropics, but is far more abundant in the Old World than in tropical 

 America. Its members are climbing shrubs, having trunks 3 or 4 feet 

 in height and about 4 inches in diameter; the trunks send out numer- 

 ous long branches, which climb over the neighboring vegetation, and 

 the tips of which hang freely downward. 



Watt (io,p.8oy describes Derris as a genus of arborescent climbers or 

 trees, and states that the roots of Derris elliptica furnish a useful insec- 

 ticide for gardening purposes. A number of other species are mentioned 

 in the literature as being used for fish poisons, and in some cases reference 

 is made also to their use as insecticides; but these cited cases seem 

 to be no better than mere reports. Correspondents in the Philippine 

 Islands and Java report that D. elliptica is probably the species most 

 commonly used as a fish poison. In all cases, so far as known, only 

 the roots are employed. It seems that the most widespread treatment 

 is one in which the roots are buried in mud, brackish mud preferred, 

 for a period of several weeks; then the roots are crushed and placed in 

 water inhabited by fish. The roots of Derris, in all probability D. ellip- 

 tica, are used as insecticides in the Dutch East Indies; and a correspond- 

 ent reports that Derris is commonly used by the Chinese gardeners in the 

 Malay Peninsula as an insecticide and that the parts of the plant used 

 are sold by Chinese storekeepers. However, it is said that the poison 

 loses its activity when the plant is dried. 



Hooker (5, p. 43) reports on a specimen of Derris elliptica, obtained 

 from Singapore where it is known as "tubah" and where it is used as 

 an insecticide ; the roots are steeped in water and the resulting decoction 

 is said to be an efficient insecticide for garden purposes. 



' No record of the publication of these specific names could be found. 

 ^ Reference is made by number (italic) to "Literature cited," p. 200. 



