506 BACTERIOLOGY. 



ture of 42.5 C. Study each flask carefully, both in 

 its culture-peculiarities and in its pathogenic properties 

 when employed on animals. 



Are these cultures identical in all respects with those 

 that have been kept at 37 C.? 



If they differ, in what respect is the difference most 

 conspicuous ? 



Should any of the animals survive the inoculations 

 made from the different cultures in the foregoing ex- 

 periment, note carefully which one it is, and after ten 

 to twelve days repeat the inoculation, using the same 

 culture ; if it again survives, inoculate it with the cult- 

 ure preceding the one just used in the order of removal 

 from the incubator ; if it still survives, inoculate it with 

 virulent anthrax. What is the result? How is the 

 result to be explained? Do the cultures which were 

 made from these flasks at the time of their removal 

 from the incubator act in the same way toward animals 

 as the organisms growing in the flasks ? Is the action 

 of each of these cultures the same for mice, guinea-pigs, 

 and rabbits? 



Prepare a 2 per cent, solution of sulphuric acid in 

 distilled water ; suspend in this a number of anthrax 

 spores ; at the end of three, six, and nine days at 35 C. 

 inoculate both a guinea-pig and a rabbit. Prepare 

 cultures from this suspension on the third, sixth, and 

 ninth days ; when the cultures have developed inoculate 

 a rabbit and a guinea-pig from the culture made on the 

 ninth day. Should the animals survive, inoculate them 

 again after three or four days with a culture made on 

 the sixth day. Do the results appear in any way 

 peculiar ? 



