BLOOD SERUM— TUBERCLE BACILLUS. 105 



the lower part of the test-tube. It in no way modifies the clearness 

 of the liquid, nor will it mingle with it, but is torn up and washed 

 away in flakes, should the water be allowed to trickle over the surface 

 of the serum. The same organism can be advantageously cultivated 

 in sterile capsules of solidified serum (see Fig. 56), when it presents 

 similar features, which can here be studied to even greater advantage 

 than when it is grown in test-tubes. 



