52 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



and ascertained by many competent observers, amongst 

 whom particularly Cohn and Koch may be mentioned. 



If we then find, as is the case with the various species of 

 micrococci and Bacterium termo, that a culture of an 

 organism, kept under the most favourable conditions for the 

 formation of spores, loses after some time the power of 

 starting a new crop in a suitable medium, we are justified in 

 saying that in such a culture no living or life-giving particle 

 is present, no spore has been formed. Looked at from 

 this point of view, I am in agreement with Koch, who from 

 experimental observations (described on a former page) 

 denies the formation of spores in the comma-bacilli and 

 spirilla. I have had during the last four years a large 

 number of culture-tubes of comma-bacilli in gelatine and 

 Agar-agar mixture, which after several months proved barren 

 of all life, although they were once good and active cultures. 

 I have had cultures made in Bombay during September 

 1884, which for some months contained a copious crop 

 of living choleraic comma-bacilli. After my return to Eng- 

 land in January 1885, they were tested and were found 

 capable of starting active and good fresh cultures of comma- 

 bacilli. And so they were found till May 1885, i.e. after 

 nine months. But after this time all life in them became 

 extinct. Subsequent experiments carried on on a large 

 scale have confirmed this ; many tubes tested in this respect 

 were, before the end of twelve months or earlier, proved 

 barren of all life. As regards gelatine-tubes, such a 

 condition, i.e. death of the growth, sets in in many instances 

 after four to five months, in others after six to eight months. 

 (Compare also E. Weibel's observations of other vibrios.) 



Now from a morphological point of view it can be easily 

 ascertained that in almost all culture-tubes, say in gelatine 

 tubes after two to three weeks, in Agar-agar tubes kept at 



