STUDIES OF SPORE-PLANTS 297 



are increased in strength with each successive injection, is 

 that the person injected acquires immunity; that is, he 

 probably develops an anti-toxin faster than the toxins intro- 

 duced by the saliva of the rabid dog can act. At present 

 no other method of dealing with this terrible disease is known, 

 and hence it is important that protective inoculation be 

 applied as soon as possible. But much common sense is 

 needed in dealing with dog bites. There is no foundation 

 for the idea that dogs are liable to go " mad " in " dog days." 

 Most dogs which bite or appear sick are not rabid. Hydro- 

 phobia is a rare disease. One who is bitten by a dog should 

 have the wound properly treated by a surgeon, for blood- 

 poisoning bacteria may get into any deep wound. If the 

 dog shows signs of illness, it should be kept in confinement 

 for some days ; for if it is rabid, the disease will develop 

 rapidly. If the dog has been killed, its body should be 

 expressed, packed in ice, to the nearest Pasteur Institute or 

 health laboratory. Microscopic examination of the nervous 

 organs will show whether the dog had hydrophobia, and it 

 can be quickly determined whether protective inoculation 

 should be given to the person who was bitten. 



References : Limited space has made it necessary to con- 

 fine this chapter to statements of general principles regard- 

 ing bacteria. Some practical notes on bacteria and human 

 health are given in the next part of this book ( 482-490). 

 Sternberg's " Infection and Immunity " is a good popular 

 account of bacteria and disease. Jordan's " General Bac- 

 teriology " is an excellent semi-technical book. 



