No. 4.] REPORT OF CATTLE BUREAU. 11)3 



and the Chief of the United States Bureau of Animal In- 

 dustry, As can well be imagined, these officials have been 

 very busy, and in many instances it has taken time to obtain 

 the information desired. 



This outbreak of foot-and-mouth disease is interesting be- 

 cause it gives rise to the question, how can a disease that was 

 not known to exist on this continent, but that would have to 

 be imported from abroad, probably from Europe or Asia, sud- 

 denly make its a])i)earance here, and at a point so remote from 

 the seacoast ? 



When the outbreak of epizootic aptha in Massachusetts 

 occurred during the winter of 1902 and 1903, it was sup- 

 posed at that time that it must have been brought here in hay 

 or straw used for packing merchandise, thrown out upon the 

 docks at East Boston and taken to Chelsea by some thrifty 

 Hebrew cow owner, and that cattle thus infected started the 

 outbreak. 'Ro other possible solution of the question would 

 ever have been thought of if it had not been for the experi- 

 ments of Dr. Ernest E. Tyzzer at his father's farm in Wake- 

 field in the sunmier of 1003, a full account of which is given 

 in the fourth semiannual report of the Chief of the Cattle 

 Bureau to the State Board of Agriculture. Dr. Tyzzer was 

 at that time making a study of smallpox, and his investiga- 

 tions included a study of vaccine virus. In making some 

 inoculation experiments on calves he started an independent 

 outbreak of foot-and-mouth disease at his father's farm. The 

 United States Bureau of Animal Industry and the Massa- 

 chusetts Cattle Bureau then hired a little place at Wakefield, 

 and bought three cows and three calves and took them there. 

 Dr. Tyzzer then repeated his experiments with the same vac- 

 cine virus, with the same results. The following is an extract 

 from the report above referred to : — 



It is perfectly evident, from the results of these experiments, that 

 vaccine virus may become contaminated with the ^^rus of foot-and- 

 mouth disease, and convey the latter through the medium of animals 

 used for the production of vaccine virus. This accidental discovery 

 may be the solution of the cause of the original outbreak. 



As nearly as can be ascertained, the first place for foot-and-mouth 

 disease to make its appearance was upon the premises of the late 



