into the United States. At the same time the state of Massachusetts appropriated $10,000 a year for three years for the same end. A special superintendent, Mr. Kirkland, with a staff of agents and assistants, was charged to preside over the execution of the work in America, and Mr. Howard, during the three years 1905, 1906 and 1907, was sent on a mission to Europe to seek for the parasites of the two species, visiting France, England, Italy, Germany, Austria, Hungary and Russia. He interested in his enterprise all of the official entomological bureaus, as well as the principal specialists, who promised him their help and active cooperation.
It is by hundreds of thousands that the nests of the brown-tail moth have been sent to Boston for two winters. It is in innumerable quantities that, during the months of June and July, caterpillars and chrysalids of the two species have been sent to both destinations. All these insects, upon their arrival in Boston, where they have been received by Mr. Kirkland, are sent to a laboratory specially constructed for this work. It is in the suburbs of a small village named Saugus, in a house which is constructed in the midst of woods infested by the caterpillars of the two species. Aside from the rooms devoted to research and rearing work, this house contains the local or resident assistant, who has charge of the work, and also the specialists who are sent by the bureau from Washington, at the time when the insects are appearing. The insects are reared in boxes constructed for that purpose, and somewhat like those employed by the State Board of Horticulture of California. To avoid the issuing of hyperparasites or of suspected species not existing in America, and accidentally mixed with the sendings, the cages are kept in closed rooms with double doors. They are arranged side by side in several longitudinal rows, and so abundantly that it is difficult to walk between them. When issued, the parasites are generally not set at once at liberty, but are allowed to breed in large outside cages.
To what practical results will these experiments conduct us? It is difficult to answer this question in a decisive way. The experiments have been in any case carried on under conditions most perfectly constituted to assure the success of the enterprise, and it was impossible to confide their execution to a savant of greater authority than the eminent director of the Bureau of Entomology, at Washington. Having a great number of parasites imported, an abundance of food which they find at their disposition, and a climate which they will encounter analogous to that of Europe, it does not appear doubtful that many species will acclimatize themselves, and as soon as acclimatized, they can not fail to strongly influence the balance of nature to the prejudice of the destructive species.
The time necessary for this movement of the see-saw may be long,