EXTRACTS AKD DECOCTIONS OF DIFFERENT PLANTS. 185 



applied affects and kills by contact very young worms, but has little or 

 no effect upon the average sized and full-grown ones. They do not feed, 

 however, for a considerable length of time^ changing their places in 

 search of fresh leaves." [E. A. Schwarz.] 



Prickly ash (Zanilioxylum carolinianum). Powdered leaves. 

 *' Seemed obnoxious to the worms." [J. P. Stelle.] 



Smartweed [Polygonnm hydropiper). Decoction of leaves and alco- 

 holic extract. IsTo result. 



Mullein ( Verhascum thapsus). Alcoholic extract and decoction of 

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



Pennyroyal {Hedeoma pulegioides). Alcoholic extract, decoction, and 

 infusion. No result. [E. W. Jones.] 



HoRSEMiNT {Monar da punctata). Alcoholic extract of leaves. No re- 

 sult. [E. A. Schwarz.] 



HoREHOUND {Marruhium vulgare). " This decoction emits a very pow- 

 erful and disagreeable stench, which I could still smell on the cotton- 

 plants two days after aiDplication, but it had no effect whatever on the 

 worms, nor did it prevent the moths from ovipositing. The alcoholic 

 extract did not possess this unpleasant smell, and had likewise no effect 

 whatever." [E. A. Schwarz.] 



China tree [Melia azedaracli). " I sprayed a decoction of leaves and 

 small twigs on the cotton i)lants, and I think it had a large effect in 

 preventing the moths of Heliothis and Aletia from ovipositing, but it 

 did not destroy the larvae. The alcoholic extract of the berries and 

 leaves adulterated with twice its quantity of water was sprayed on 

 twelve Aletia larvae, full-grown; most of them fell to the ground, and four 

 died. This experiment was repeated with about the same result; but 

 when the extract was diluted with ten parts of water it failed to bring 

 the worms to the ground." [E. W. Jones.] '^This plant, in the form of 

 alcoholic extracts as well as decoctions, undoubtedly possesses some in- 

 secticide properties, acting upon the worms by contact, but in a manner 

 quite different from pyrethrum and kerosene. The acting principle 

 seems to be of a narcotic nature, the worms not showing any unusual 

 disturbance after application. They seem to get benumbed, and, gradu- 

 ally losing their strength^ finally loosen their hold and drop to the ground, 

 where they lie without falling in convulsions. The more full-grown 

 worms are, however, but little affected, and of the smaller ones a large 

 proportion recover. This is the most promising plant of the whole 

 number I experimented with, though the extracts and decoctions as ap- 

 plied by myself are altogether too weak to be used as a remedy for the 

 worms. The preparations made from the berries are evidently more 

 effective than those from the leaves, and the extracts and decoctions 

 made by Mr. Eoane proved to be more effective than those I received 

 from Prof. E. W. Jones, of Oxford. For further experiments I would 

 recommend preparations from the dried green berries." [E. A. Schwarz.] 



