QUESTIONS 173 



a portion will be of such quality that they can be used. The collodion 

 sacs are then filled with nutrient bouillon and placed in larger test 

 tubes containing the same bouillon. Both the glass tube and the 

 test tube are cotton plugged, and then sterilized and cooled. Later 

 the collodion sacs can be inoculated with the platinum rod. They 

 must then be taken out of the tubes and dried externally with sterile 

 cotton and the constriction heated over a flame, drawn out and 

 securely sealed. They are now ready for implantation into the peri- 

 toneal cavity of an animal. 



Non-pathogenic bacteria in collodion sacs implanted in the peri- 

 toneal cavity of an animal can be so changed that they acquire 

 pathogenic properties, and after removal from the animal and sub- 

 sequent inoculation in another animal of the same species they will 

 produce disease because they are able to multiply and resist phago- 

 cytosis. 



QUESTIONS. 



|1. How can a bacterium obtained in pure culture from some pathologic 

 product be fully identified? 



2. What are the different changes in appearances produced by bacteria 

 (a) in nutrient bouillon ? (b) in milk ? 



3. Explain the meaning of the following terms used with reference to a non- 

 liquefying growth of a bacterium in gelatin : Filiform, nodose, beaded, papillate, 

 echinate, villous, arborescent, plumose. 



4. Explain the meaning of the following terms, used with reference to the 

 liquefying growths in gelatin : Crateriform, tubular, cylindrical, saccate, infun- 

 dibular, conical, fusiform, stratiform liquefaction. 



5. What features should be noted in a gelatin shake culture? 



6. What features should be noted in the condensed water of an agar slant? 



7. What arrangement offers the best chances to study the characteristics of 

 individual colonies? 



8. Explain the following terms used in the description of bacterial colonies: 

 Round, elliptical, fusiform, irregular, cochleate, ameboid, myceloid, filamentous, 

 floccose, rhizoid, conglomerate, toruloid, rosulate. 



9. What is meant by a colony "resembling the head of a Medusa?" Name 

 a bacterium forming such colonies. 



10. What terms are used with reference to the different types of elevations 

 of colonies over the surface of the culture medium? 



11. What are the meanings of the following terms: Alveolate, punctate, 

 bullate, vesicular, verrucose, squamous, echinate, papillate, rugose, corrugate? 



12. What terms are used in the description of the margins of colonies? 



13. Explain the following terms: Reticulate, areolate, gyrose, marmorated. 



14. For what purposes are animal experiments made in bacteriologic studies. 



15. Describe the subcutaneous method of inoculation. 



16. The intraperitoneal method. 



17. The intravenous method. 



18. The subdural method. The method of inoculating into the spinal canal. 



19. How is a small animal restrained for inoculation? 



20. What precautions are used to avoid injuries in intraperitoneal inoculation? 



21. What is a "Normaloese ?" What is the object of using it? 



22. What other methods are used to inoculate a definite amount of a bacterial 

 growth ? 



23. Describe the method of preparing collodion sacs. 



24. What is the object of using them? 



