THE GERM THEORY 385 



development by fission: conditions are different when the 

 vibrios are transformed into their germs, 4 that is into the 

 glistening corpuscles first described and figured in my studies 

 on silk-worm disease, in dealing with worms dead of the 

 disease called " flacherie." Only the adult vibrios disap- 

 pear, burn up, and lose their virulence in contact with 

 air: the germ corpuscles, under these conditions, remain 

 always ready for new cultures, and for new inoculations. 



All this however does not do away with the difficulty 

 of understanding how septic germs can exist on the surface 

 of objects, floating in the air and in water. 



Where can these corpuscles originate? Nothing is easier 

 than the production of these germs, in spite of the presence 

 of air in contact with septic fluids. 



If abdominal serous exudate containing septic vibrios 

 actively growing by fission be exposed to the air, as we 

 suggested above, but with the precaution of giving a sub- 

 stantial thickness to the layer, even if only one centimeter 

 be used, this curious phenomenon will appear in a few 

 hours. The oxygen is absorbed in the upper layers of 

 the fluid as is indicated by the change of color. Here the 

 vibrios are dead and disappear. In the deeper layers, on 

 the other hand, towards the bottom of this centimeter of 

 septic fluid we suppose to be under observation, the vibrios 

 continue to multiply by fission protected from the action 

 of oxygen by those that have perished above them: little 

 by little they pass over to the condition of germ corpus- 

 cles with the gradual disappearance of the thread forms. 

 So that instead of moving threads of varying length, some- 

 times greater than the field of the microscope, there is to 

 be seen only a number of glittering points, lying free or 

 surrounded by a scarcely perceptible amorphous mass.* 

 Thus is formed, containing the latent germ life, no longer 

 in danger from the destructive action of oxygen, thus, I 



4 By the term* " germ ** and " germ corpuscles," Pasteur undoubtedly 

 meant " spores," but the change is not made, in accordance with note a, 

 above. Translator. 



1 In our note of July i6th, 1877, lt l * "tated that the septic vibrio is not 

 destroyed by the oxygen of the air nor by oxygen at high tension, but that 

 under these conditions it is transformed into germ-corpuscles. This is, 

 however, an incorrect interpretation of facts. The vibrio is destroyed by 

 oxygen, and it i* only where it is in a thick layer that it is transformed to 

 germ-corpuscles in the presence of oxygen and that its virulence is preserved. 



(13) HC XXXVIII 



