Commissioner of Agriculture 326 



infection, have been clearly brought out; every animal or thing 

 moved from the suspected place, since that date must be carefully 

 followed, and every side issue in the way of a possible diverging 

 stream of infection must be treated in the same manner until 

 every channel offering a chance of diffusion of infection has been 

 fully guarded. 



Live stock that arrived by rail just before and since the time of 

 the advent of infection can be traced back by the waybills to their 

 starting point from the farm. The cars they have come by can be 

 identified and held for disinfection. If they have carried other 

 stock since the suspected shipment, these can be traced to their 

 destination and subjected to investigation, together with any other 

 live stock that they have come in contact with, or that have come in 

 contact with any place or thing that they may possibly have con- 

 taminated, and the inquiry must be made to branch along other 

 lines of trade and travel from any point at which there has 

 apparently been an opportunity for infection to pass from animal 

 to animal. When an animal is being traced back in this way from 

 infected stock yards, any point where it has been stopped for rest, 

 food or water, must be taken as a new center for lines of inquiry 

 which must be started at that point; all live stock that have passed 

 through the detention buildings or yards for two weeks before our 

 herd, and all since, being subjected to the same modes and lines 

 of inquiry as advised for the herd with which we started. Find 

 the numbers and destinations of all cars that have brought live 

 stock or taken them from such places of detention and have them 

 traced and disinfected. 



Coining back to the suspected stock yards from which we 

 started, find out the exact yards occupied by the suspected stock, 

 the alleys, loading banks, and chutes through which they were 

 passed on arrival and dismissal, shutting these up and disinfect- 

 ing them. Then trace every animal that has, since the suspected 

 herd, been in contact with the suspected yards, the loading banks, 

 chutes, etc., or with the manure or litter taken from the same, and 

 make thorough investigation of every exposed beast and thing that 

 could by any possibility have contracted or carried infection from 

 this source. At this stage the commission men's records of sales, 

 the steelvard's record of weights, and the railroad's record of cars, 



