DISSEMINATORS OF DISEASE 63 



furthermore, the worst inflammatory wounds not 

 uncommonly show feverish symptoms of a well marked 

 periodic character, quiescent intervals being followed 

 by revived inflammation in the same spot. These facts 

 almost prove, or at least strongly suggest, an explana- 

 tion that in the latter cases the source of pathogenic 

 trouble is of a microbic character, and that periodic 

 recurrence of feverish and inflammatory symptons is 

 the time of the spore-swarming of breeding microbes ; 

 the difference between these latter and those of a more 

 severe and often fatal kind in the tropics being that 

 the one class finds the human body a fit host in which 

 to multiply but the other class does not, and accord- 

 ingly the latter grow weaker until their breed dies out. 

 Similar effects can be observed in cattle and other 

 animals, but all creatures, after suffering much from fly- 

 bites at first, afterwards become for a time more or less 

 immune. 



