8 BULLETIN 824, U. S. DEPARTMENT OF AGRICULTURE. 
In some districts a simpler method of harvesting is adopted. At the time of full 
bloom, the flowers, together with their leaves and stems, are reaped about twice, with 
a tool like a short-handled rake with comb-shaped teeth, and dried in the sun. It 
should be added that powder made from flowers picked by this comb-toothed instru- 
ment is either inferior or no good, for the reason that flowers in all stages of bloom- 
ing are thereby picked, whereas to obtain the full strength flowers must be picked 
at exactly the right stage of blooming, which can be done only by hand. 
The flowers picked are spread on straw mats and dried in a sunny place, exposed 
to the wind. Then they are moved to a drying room, which should have a good 
draft. Shelves, similar to those used in sericulture, are made by laying down 
rush screens or old newspapers on the top, where the flowers are arranged thinly and 
turned over twice or more a day. A few days later, when dried to a certain extent, 
they may be spread out thicker than at first. The drying is finished in 6 or 7 days. 
When there is no drying room, they are dried entirely in the sun. By adopting this 
system, a much greater quantity can be dried in a shorter time, although it is inferior 
in quality compared with that dried in the shade. Drying in the sun takes only three 
days in fine weather. If the drying takes too long, the flowers lose their strength 
Drying has reached the proper stage when the flowers can be roughly powdered by 
breaking them into small pieces upon rubbing with the thumb and forefinger. Arti- 
ficial heat is also applied at large factories, the standard of the heat being 150° F. 
In addition to the districts named by West, the provinces of Ki-i 
and Mikawa are mentioned by Fujitani (89) as supplying flowers. 
Herrera (129) states that the O. cinerarixfolium grows well in Mexico. 
Efforts to introduce the cultivation of Pyrethrum into this country 
were made by the United States Department of Agriculture as early 
as 1859. In that year Bishop (30) reported that 250 plants of Pyre- 
thrum caucasicum were in the course of cultivation in the Experimental 
and Propagating Garden at Washington, D. C. Markoe (188) de- 
scribes the growing of Pyrethrum roseum by Prof. Asa Gray in the 
Cambridge, Mass., Botanical Garden from seeds distributed by the 
Government in 1859. The seeds yielded by the American-grown 
plants were sown but did not germinate. The root stocks of the old 
plants, however, threw up shoots in the second year. Gray was of 
the opinion that the cultivation of the plant could be made profitable 
in this country. In 1860 Abel (1) stated that he was informed by 
persons receiving some of this seed that the plants were in a flourish- 
ing condition. In the eighties the United States Department of 
Agriculture renewed its efforts to establish the cultivation of insect- 
powder-producing plants. In Washington, D. C, Riley (222) 
obtained good results. He distributed seed to correspondents in 
Alabama, California, Dakota, Georgia, Illinois, Indiana, Iowa, 
Kansas, Kentucky, Maryland, Michigan, Mississippi, Missouri, New 
Hampshire, New Jersey, New York, North Carolina, Ohio, Ontario, 
Pennsylvania, Vermont, and Virginia, but in all the States, except 
California, the results were unfavorable, due, apparently, largely to 
drought and bad seed. 
