154 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



celed and 5 suspended, the latter for violations of the department's 

 re<;ul:itions. Fifty-ei<2:lit of the licensed establishmients produced 

 only antiho<]:-cholera serum and hog-cholera virus, 29 produced other 

 products only, while G produced both classes of products. To super- 

 vise these establishments and products the bureau maintained 17 sta- 

 tions and 42 substations in 58 cities and towns in 20 States. 



Serum and virus for the prevention of hog cholera form a large 

 part of the volume of products supervised. The production of anti- 

 hog-cholera serum amounted to 525,043,761 cubic centimeters, of 

 which 5.057,120 cubic centimeters was destroyed as unfit for use, and 

 in addition 3,557,120 cubic centimeters of blood was destroyed when 

 collected, on account of disease or other conditions existing in the 

 animals from which it was collected. The quantity of simultaneous 

 virus produced was 22,838,784 cubic centimeters, of which 1,102,645 

 cubic centimeters was destroyed as unfit for use, and in addition to 

 which 330,331 cubic centimeters of blood was destroyed when col- 

 lected. The production of hyperimmunizing virus was 114,180,172 

 cubic centimeters, of which 271,460 cubic centimeters was destroyed 

 as unfit for use, and in addition to which 7,719,425 cubic centimeters 

 of blood was destroyed when collected. To determine the potency 

 and purity of the serum and the purity of the virus 7,770 tests of the 

 former and 1,228 of the latter were made. There were inspected and 

 admitted to the premises of licensed establishments for use in the pro- 

 duction and testing of the serum and virus 314,706 hogs and 2,918 

 calves, and 24 hogs and i calf were rejected. In subsequent opera- 

 tions 19,323 additional hogs were rejected. 



During the year 866 subcultures involving 1,037 strains of organ- 

 isms used in the production of licensed products were collected and 

 submitted for laboratory examination. Of the strains, 800 were 

 found to be satisfactory and 237 unsatisfactory. 



EXPERIMENT STATION. 



The work of the Experiment Station at Bethescla, Md., in charge of 

 Dr. E, C. Schroeder, superintendent, has consisted mainly of investi- 

 gations made both independently and in cooperation with other 

 divisions, concerning infectious diseases of domestic animals, and the 

 provision of facilities for other divisions to make observations on 

 animals under normal farm and field conditions. 



ABORTION DISEASE. 



Studies concerning the etiology of infectious abortion disease of 

 cattle, which have been in progress several years, were continued. 

 The results are quite encouraging, as they indicate that much can be 

 done to reduce losses by the use of relatively simple measures directed 

 against the dissemination of the microorganism on which its occur- 

 rence primarily depends. Many careful tests have been made to 

 determine through what channels the' microorganism leaves the 

 bodies of infected cattle, and only three have been definitely proved, 

 namel}^, the reproductive organs of coavs at and for a short period of 

 time after a parturition or an abortion, the udders of infected cows 

 for a period of time that may vary from a few days to seven or eight 

 years, and the discharges from the reproductive organs of infected 

 bulls. It has also been conclusive!}^ shown that the easiest natural 



