196 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



taking during the past fiscal 3'oar, as a result of which areas aggre- 

 gating 10,965 square miles were released from quarantine, making the 

 total territory so released since the beginning of the work 139,821 

 square miles. This territory is mostly along the northern border of 

 the infected region, extending from Virginia to California. 



Experiments in dipping cattle for the destruction of the ticks have 

 shown that arsenical solutions are more satisfactory than the Beau- 

 mont crude petroleum which has heretofore been used to a consider- 

 able extent. Arsenic{>l dips are thend'ore now })eing principally 

 employed in the work of tick eradication, and articles have been pre- 

 pared for ))ublication reporting the results of the dipping experiments 

 and giving directions for the preparation and use of arsenical dips and 

 for the construction of dipping vats. A paper discussing the history 

 and progress of the work of tick eradication has also been prepared 

 for the Twenty-seventh Annual Kcport of the Bureau. 



Substantial progress was also made during the fiscal year in the 

 eradication of the parasitic diseases known as sheep scab and cattle 

 mange. Statistics of this work, as well as of tick eradication, appear 

 in the portion of this report dealing with the work of the Inspection 

 Division. In addition to the territory released from quarantme, the 

 a-mount of infection in some of the areas remaining under quarantine 

 has been considerably reduced. 



The form of necrobacillosis known as lip-and-leg ulceration of 

 sheep, which has been quite prevalent in a malignant form in a large 

 part of Wyoming and Montana within the past three years, was 

 brought under control so well during the fiscal year as a result of 

 work done by the bureau and State officers, with favorable climatic 

 conditions, that the Federal quarantine was entirely released under 

 date of August 10, 1911. While the disease is still sometimes found 

 in a mild form, it is believed that ordinary methods of State and 

 interstate inspection will be sufficient to keep it under control. It is 

 fortunate for the sheep industry that the malignant form of the dis- 

 ease was stamped out within such a short time and not allowed to 

 spread extensively throughout the West. 



The recurrence of the contagious disease known as dourine of 

 horses was an incident of the year. This disease had apparently 

 been completely eradi(^ted a few years before as a result 01 several 

 years' work by the bureau. The new outbreak occurred in Iowa, 

 and while the manner in which the infection was again introduced 

 has not been positively determined, all the information at hand points 

 to its having been brought in with an imported stallion. Prompt and 

 vigorous action by the bureau in concert with the State authorities 

 has resulted in the practical eradication of the contagion. In study- 

 ing the disease the scientists of the bureau were able to find under 

 the microscope the living organisms wliich are the infective agent, 

 this being the first discovery of the organism in natural cases in the 

 United States. Further details of the outbreak and its study and 

 eradication are given in the rejiort of the Pathological Division. 



Although mallein has been in use for the diagnosis of glanders for 

 several years, it has not been entirely reliable. During the year the 

 bureau scientists have made a special study of a new laboratory test 

 for glanders known as the complement-fiiation test, and the first 

 descri})tion of this test published in the United States was issued as 

 a bulletin of the bureau. The new test has been found to be highly 



