No. 7. DEPARTMENT OF AGRICULTURE. 



NO. 111. IMMUNIZED (BATTLE FREE t)F TUBERCULOSIS 



163 



Animal 



(a) 



No. fi61 Grade Heifer, - 



- No. 74a Grade Steer,.. 



No. 776 Grade Steer,. 



No. 784 Grade Steer,. 



No. 783 Grade Steer,— 



No. 738 Grade Steer, .. 



No. 747 Grade Heifer,. 



No. 739 Grade Heifer,.. 



No. 786 Jersey Heifer... 



Coucliisimis. 1. The iiiicrosc()i)ic examination of the feces or rec- 

 tal scrapings of cattle for tubeicle bacilli is of no value, in that many 

 bacteria make their apiiearance in the feces of rectal scrapings, with 

 the morpliology and staining characteristics of tubercle bacilli which, 

 lioAvever, fail to prove themselves as such. 



2. "The animal inoculation test," i. e., the injection of guinea 

 ];igs with feces and rectal scraj)ings of cattle is a valuable, although 

 not an infallible test. It can be relied upon when the guinea jngs in- 

 jected develop tuberculosis as a result of the injection. Feeding 

 malerial suspected of containing tubercle bacilli to guinea i:igs has 

 shown itself of little value, in that cmly 3 (20 per cent.) of the guinea 

 }(igs fed feces with tubercle bacilli developed tuberculosis. 



3. Of the forty cattle included in the examination, 9 (22.5 per 

 cent.) were found to be throwing off virulent tubercle bacilli in the 

 feces or rectal scra])ings. Of these 1) cattle, the tubercle bacilli were 

 found viiuleul for guinea pigs, and in S of 0. the tubercle bacilli 

 were virulent for rabbits. 



