gradual passage through the several stages of cultivation, and finally their dispersion, in their cultivated condition, whither I could not certainly say, but presumably to the ends of the earth.
One thing especially puzzled me: I could not estimate at all the amount of time which the process of cultivation consumed in the case of each germ. There were germs constantly going into cultivation and frequently coming out; but how long it was from the time that each one went in until the same one came out again, whether they took different periods of time or uniform, or nearly uniform periods, I could not at all guess. The rapidly decreasing size of the beds implied certainly that the process of cultivation was a process of elimination. It seemed that not one in a hundred of those which passed through the first stage could ever have reached the final stage. And I think also that it might be inferred with much probability from the same fact that the process of cultivation lasted in most cases for a long time. For otherwise they might surely have made up for losses during culture by an increase of the numbers put under cultivation. For what I saw left me no room to doubt that such an increase in quantity was at their disposal. Making a rough estimate, I should say that hundreds of germs
