42 
6 p.m. The first worm ceased feeding and left; can not be found. The second was: 
entirely in boll, but came out and is twisting abont uneasily; finally it fell to the: 
ground in convulsions, tumbling over on its back as if to scrub off the powder. The: 
third ceased feeding. The fourth was a young worm and is not to be found. The fifth 
still feeding. 
6:15. The second is still in convulsions and can not crawl well; it is one about 
two-thirds grown. The third has fallen to the ground, but is crawling into loose 
earth. The fifth continues feeding. The last two are nearly grown worms, and 
doubtless will take some time to become badly paralyzed. At 6:30, while making: 
other observations, it became dark, and could not find the worms again. 
A number of individual experiments with grown worms, both in the 
laboratory and open air, were made. The worms were well dusted with 
full-strength pyrethrum and were allowed their pleasure as to their 
abode afterwards. They always crawled into the loose earth as soon 
as possible, and as long as they were observed showed signs of recovery. 
Other experiments similar to Experiment 9 are omitted because their 
results were practically the same in all cases. 
DECOCTIONS OF PYRETHRUM. 
Seven pints of rain water were brought to boiling in an open pan ; 
12 grains of pyrethrum were then stirred in and boiled for 15 minutes. 
The whole was then strained so as to get out most of the powder. This 
decoction was made on the afternoon of September 19, but owing toa 
threatening rain was kept in sealed Mason jars until the next day, when 
the decoction was sprayed on bolls containing Boll Worms. The fol- 
lowing strengths were used: Full, two-thirds, and half. 
{XPERIMENT 15. 
September 20. The bolls with worms in had all been found and marked during 
the forenoon. The day was warm and sunshiny. In thé afternoon it was found that 
one of the worms had changed bolls since morning observation. At 2:40 p. m. full 
strength of the decoction was sprayed on each of six bolls containing Boll Worms. 
Four of the six were not in bolls, but between them and their involucres. The 
greater portion of the plants surrounding the boll was also sprayed. 
2:50. No uneasiness manifested by any. 
3:15. Five as before; one half-grown worm has moved and can not be found. 
3:45. No change; has not affected the worms yet. 
4:10. None feeding ; no change. 
5:00. One feeding; others as before. 
5:50. None feeding. 
September 21. Two worms still in place; one feeding, the other just molted; two 
others finished the bolls in which they were found and have disappeared; the other 
one is in boll in laboratory. 
September 23. All have gone but one; this one went to another boll, fed, and has 
just molted; an hour later it was found devouring molted skin. 
EXPERIMENT 16. 
September 20. Equal parts decoction and rain water. At3o’clock sprayed five 
bolls, each containing a Boll Worm. Four were not feeding, but resting between boll 
and involucre; the other was in boll feeding. None had changed position since 
morning observation. 
