SPIRILLA. 205 



How are animals affected by feeding of the bacilla ? 

 Where is the toxin of the Bacillus dysentericse contained? 

 May animals be immunized against dysentery by inoculation with Bacil- 

 lus dysentericse ? 



What claims are made for the serum of inoculated animals? 



Hog Cholera. 



By whom was the bacillus of hog cholera discovered ? 

 Give its morphology. Its staining. Its principal biologic characters. 

 How does it grow on gelatin and agar ? On potato ? In bouillon ? In 

 milk? 



Does it produce gases? 



What is its thermal death-point? 



How does it affect laboratory animals? 



Has immunity been produced by injections of cultures of this bacillus ? 



Has a toxin been isolated from the bacillus of hog cholera ? 



What are the properties of the serum of immunized animals ? 



Describe the Morax-Axenfeld bacillus. 



Chicken Cholera. 



By whom was the Bacillus choleras gallinarum discovered, and by whom 

 described ? 



Describe this bacillus. 



How does it stain ? 



Give its principal biologic characters. 



What is the appearance of the cultures on gelatin to the naked eye ? How 

 do they look when seen under the microscope? 



What animals are subject to infection ? Which animals are immune? 



What sort of infection is produced in animals by the inoculation of this 

 bacillus ? 



What is effected by feeding animals with material contaminated with this 

 bacillus ? 



How are protective inoculations performed? 



To what extent is this bacillus pathogenic to rabbits? 



Under what different names has this bacillus been described by various 

 authors ? 



CHAPTER XXIII. 

 SPIRILLA. 



ALTHOUGH spirillse and spirochsetae are divisions of the 

 spirillacese and belong to the bacteria, there are several 

 organisms which are labelled spirochsetse and spirillae about 

 whose vegetable nature there is a considerable doubt. The 

 difficulty attending their classification is increased by the fail- 



