The First Land Plants 



best explained in the same way. The new stock are all 

 a strong selected race, and all weakly birds have been 

 killed out. 



One might, I think, find many facts in the history of 

 man which are explained in the same way, such as the 

 development of modern Germany after the Franco- 

 German War ; but this is far too difficult a subject to 

 discuss here. 



Yet there are gloomy and depressing facts connected 

 with this population of bacteria. Amongst these 

 microbes there are not only friends but deadly enemies, 

 such as typhus and anthrax, which can live happily and 

 are ready for work after 500 days in garden earth. 13 



Radishes, cress, and other garden vegetables are pro- 

 bably scattered over by such germs, which are not killed 

 by ordinary kitchen manipulation. 14 



We have to thank M. Baudouin for another ingenious 

 and perfectly horrible suggestion. 



When exploring a well or rubbish pit belonging to 

 the Gallo-Roman period, he discovered some suspicious 

 mud. In this he found several dangerous disease- 

 bacteria, and kindly points out that by living in a half- 

 comatose condition, they were still prepared to start a 

 dangerous epidemic after 1800 years in the bottom of 

 a well. 15 



Fortunately eminent bacteriologists hastened to re- 

 assure the public mind by declaring that these bacteria 

 were only our own contemporaries, who had got into 

 the well with the rain-water. So that this awful fore- 

 boding of thousand-year-old bacteria still waiting to prey 

 upon us need not alarm the most sensitive person. 



1 Jacobitz. 2 Otto and Newmann. 3 Reinke. 



* Lawes, Gilbert, and Pugh. 5 Pitsch. 6 Hiltner. r Dawson. 



8 Bottomley. 9 Chittenden. 10 Errera, " Pfeiffer. 



12 Reinke. " Konradi. 14 Clauditz. 16 Baudouin. 



52 



