224 FUMIGATION METHODS 
lance in causing all Florida trees to be disinfected by 
both dipping and gas treatment. ‘The red scale of 
Florida, Aspzdiotus ficus, has been introduced on im- 
ported trees, but was without doubt eradicated by the 
gas treatment that the trees received.’ This is over the 
signature of F. Edward Gray, at that time one of the 
Horticultural Commissioners of Los Angeles County, 
‘California. In June; 1891, a shipment of 325,000 
oranges arrived at the Port of San Pedro from Tahiti, 
and were fumigated with hydrocyanic acid gas. 
‘‘ During the above years the county commissioners 
in Southern California demanded certificates that nur- 
sery stock had been fumigated or dipped. Dr. L. O. 
Howard’s history of fumigation, as printed in the ‘Year- 
Book for 1899, United States Department of Agricul- 
ture,’ is not correct. I notice on page 151 of that re- 
port that he considers, in 1894, he was the first to 
recommend fumigation of nursery stock before delivery 
to purchasers. I know that previous to 1894, as cited 
above, that hundreds of thousands of nursery trees had 
been fumigated in California before being delivered 
to purchasers. The fact of the matter is the United 
States Department of Agriculture had practically noth- 
ing to do with the discovery of the gas treatment, as 
Mr. Coquillett was not then in the employ of the 
Department.”’ 
Fumigate greenhouses regularly.—I fumigate my 
greenhouses and cold frames about four or five times a 
year with it, and have thus been able to keep down all 
insect and animal pests except the red spider. How- 
ever, about 80 per cent. of the red spiders are killed 
by the regular treatment recommended, but to com- 
