184 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



assumed that if tliere is no effect obserTable about one hour after ap- 

 plicatioD, the substance is innocuous. A general disturbance of the 

 worms immediately follows the application of any substance, however 

 harmless, and should not be taken in account. Effect through the 

 stomach is not visible until after at least twenty-four hours, and in some 

 instances not until the second or even the third day after application, 

 as the worms (prompted no doubt by instinct) do not feed upon a sub- 

 stance injurious to them until they get hungry. As to the third point, 

 almost any strange substance thrown or sprayed on the leaves stops the 

 worms from eating for a shorter or longer period, and observations as 

 to the final result must, therefore, be extended over several days. A 

 fourth point, viz., the possible influence of such applications on the ovipo- 

 sition of the moth has already been referred to. 



The following list of plants experimented with is given without any 

 systematic arrangement. If no effect on the worms was obtained by 

 several independent exi^erim enters, we have simply added ''no result." 

 Otherwise the results obtained by the individual observers are given in 

 condensed form, with the name of the observer added in brackets. 



AiLANTHUS TREE (^^ Tree of hesiYen,''^ AUanthus glandulosa). Decoc- 

 tion and infusion of leaves. Ko result.^* 



JA3IEST0WN ^^ED [Datura stramonium). Alcoholic extract from dried 

 and ground seed. No result. [R. W. Jones,] Alcoholic extract and de- 

 coction from leaves. iN'o result. [E. A. Schwarz.] 



BoNESET {Eu]^atorium perfoliatum), " Powdered leaves applied to the 

 plant seemed obnoxious to the worms." [J. P. Stelle.] Infusion from 

 leaves. Iso success. [E. A. Schwarz.] 



Dog Fennel {Selenium temiifolium and autumnale). "This plant, of 

 which I entertained considerable hopes, will render the cotton plant so 

 obnoxious that the worms won't feed upon it, but it won't kill the 

 worms." [J. P. Stelle.] Decoction, infusion, and alcoholic extract. 

 No result. [E. W. Jones and E. A. Schwarz.] Flower heads dried and 

 powdered. No result. [E. A. Schwarz.] ^^ 



CocKLEBUR {Xanthium strumarium). Alcoholic extract and decoc- 

 tion. No result. [E. A. Schwarz.] 



Buckeye {JEscuhis glabra). Alcoholic extract from fruits. No result. 

 [R. W. Jones.] Alcoholic extract and decoction of leaves. No result. 

 [E. A. Schwarz.] 



RaGt weed {Ambrosia trifida). Decoction, infusion, and alcoholic ex- 

 tract. No result. 



Hoa Weed {Ambrosia artemisicefolia). Alcoholic extract and decoc- 

 tion. No result. [E. A. Schwarz.] 



Indigo "weed {Baptisia tinctoria). Alcoholic extract and decoction. 

 No result. [E. A. Schwarz.] 



Deadly nightshade {Atropa belladonna). Decoction and alcoholic 

 extract of leaves. No result. [E. A. Schwarz.] 



Tobacco {Mcotiana tabacum). " Strong decoctdon of dry leaves freely 



