PLANTS TXSECTICIDAL PROPERTIES. 51 
Trilisa odoratissima (Walt.) Cass. Astebaceae. Carolina-vanilla. Eastern 
United States. 
Jackson (J+5) states that the leaves are used to protect woolen 
cloths from the attacks of moths. 
Triticum sp. Poaceae. Wheat. 
Scott. Abbott, and Dudley (83, p. 14) found wheat flour ineffective 
against roaches, and Abbott (1, p. 7) found it of no value against 
chicken lice, but McGregor and McDonough (59, p. 65) and others 
have found it to be an insecticide against the red-spider, although 
in this case it glues the mites fast to the foliage, thus causing death 
mechanically rather than by poisoning them. 
Tropaeolum niajus L. Gesaniaceae. Common nasturtium. Peru, culti- 
vated in gardens. 
Von Mueller (91. p. 543) reports that it has some insecticidal 
value, and it is even said that when planted around apple trees it 
will rid them finally of the woolly aphis. 
Tssikoena. ( See footnote on page 26. ) 
The writers' results are given on page 23. 
Tylophora faseiculata Ham. Asclepiadaceae. India. 
Greshoff (31. p. 108) reports that the leaves and roots are used 
to destroy rats and other vermin. 
Umbellularia calif ornica (Hook. & Am.) Nutt. Latjbaceae. Synonym: 
Oreodaphne califomica Xees. California-laurel. California to Puget Sound. 
Heamy (39) says that the tree is never attacked by insects, owing, 
as it is supposed, to the volatile oil it contains. 
Chesnut (15, p. 531) says: "The leaves appear to be very valu- 
able for driving fleas away." 
Veratrum album L. Liliaceae. White false-hellebore. White hellebore. 
Europe and northern Asia. 
The powdered rhizomes and rootlets constitute the hellebore most 
generally used as an insecticide. 
The writers' results are given on page 9. 
Veratrum californicum Durand. 
The writers' results are given on page 23. 
Veratrum nigrum L. Old World. 
Schreiber (80. 81) mentions this species and seems to think that 
it is as good as V. album for insecticidal purposes. 
Veratrum viride Ait. Synonyms: V. album ririrfr Baker. V. album Miehx. 
American hellebore. American false-hellebore, (ireen hellebore. North 
America. 
Von Mueller (91. p. 556) says that it serves like other Veratrums 
as an insecticide. 
Cook. Hutchison, and Scales (17. p. 17) say: "There are three 
plants which are popularly called hellebore, namely. Veratrwm 
album. Veratrum viride, and HeUeborus mger. The term 'helle- 
bore ' is correctly applied only to Hellebarus mger, which grows in 
