96 LABORATORY GUIDE IN BACTERIOLOGY 

 EXPERIMENT I 



a) Procure a guinea-pig (or rabbit), and clip the hair 

 over a small area on the surface of the abdomen. 



b) Cut a small opening in the skin, and separate the 

 skin from the muscles below by pushing in sterile scis- 

 sors. Expand these slightly and after closing again 

 remove. This forms a small pocket. 



c) Carry i loopful of a 24-hour-old agar-culture into 

 this pocket. 



EXPERIMENT II 



a) Heat a 24-hour-old broth-culture in the water- 

 bath for 30 minutes at 60°. 



b) Inject 0.25 c.c. of this heated culture subcutane- 

 ously into another guinea-pig (or rabbit) 



c) Observe and compare in both animals the results 

 by taking note of the ante-mortem phenomena and the 

 lesions post-mortem. What difference is there in the 

 activities of the two cultures inoculated, and to what are 

 these differences due ? 



