238 BACTERIOLOGICAL EXAMINATION OF MATERIAL 



3. To study experimentally the lesions incited by specific micro- 

 organisms. 



4. To distinguish sharply between closely related bacteria, as for 

 example, between bovine and human tubercle bacilli. Thus, rabbits 



FIG. 31. Guinea-pig dissection to show anatomical relations of internal organs and 

 important lymph glands. (From Eyre, Bacteriological Technique, Saunders & Co.) 



are susceptible to infection with bovine, but not with human tubercle 

 bacilli. Guinea-pigs are susceptible to infection with both types. 



5. To study the virulence of various microorganisms. 



6. To test the toxicity of bacterial toxins and other products, and 

 to measure the potency of curative sera. 



