24 ANNUAL EEPOKTS OF DEPARTMENT OF AGRICULTURE. 



predatory animals which cause losses of many millions each year 

 is progressing satisfactorily. 



ERADICATION OF TUBERCULOSIS. 



Gratifying progress has been made in the campaign for the eradi- 

 cation of tuberculosis. All of the States are cooperating in this 

 movement, and at the close of the year 16,216 herds had been ac- 

 credited and over 100,000 additional herds had passed a first test 

 without reactors. This widespread demonstration of the possibility 

 of freeing individual herds from the disease has resulted in increased 

 confidence in the area clean-up method. Already 23 States have 

 joined in this movement. In these States more than 150 counties 

 had completed or were in the process of testing all of their cattle 

 and nearly 300 more were making arrangements to begin the work. 

 Compared with the previous year, area testing has shown more than 

 a tenfold increase. The adoption of the area clean-up method has 

 not only reduced the expense and increased the efficiency of the work, 

 but the results already obtained have done much to strengthen the 

 belief that bovine tuberculosis can be entirely eradicated. Con- 

 clusive evidence is already at hand showing that tuberculosis in 

 swine arises principally from infected cattle and that its elimination 

 from the cattle on a given premises results in its gradual reduction 

 in the hogs. Extensive surveys show that tuberculosis is only present 

 in about 1 per cent of the cattle in 42 per cent of the areas of the 

 United States, and that in a large additional area it does not exceed 

 3 per cent. The remaining area is much more seriously affected, but 

 the evidence at hand indicates that this costly disease will finally 

 yield to the scientific methods now being employed. 



<.i^E GRADUATE SCHOOL. 



The school designed to provide graduate training for scientific 

 workers which was started in the department last year has already 

 demonstrated its usefulness in increasing the efficiency of the scientific 

 work. Also it has stimulated the younger of the scientific staff to 

 increased effort to obtain adequate training. An increasing number 

 of our scientists are taking leave of absence or arranging for part- 

 time employment to enroll in the standard graduate schools. 



This graduate school has been a factor which has made it easier 

 for the department to enlist the interest of the better class of gradu- 



