1 2 ORIGIN OF LO IV ES T OR GA NISUS. 



concerning their mutability are harmonious enough 

 with theoretical indications. 



But, as I have before indicated, although it is quite 

 true that some Bacteria develop into fungi, such forms 

 may constitute no necessary links in the life-history of 

 other fungi. I have suggested that in those (occa- 

 sional) cases in which they do occur as links in the life- 

 history of fungi, there is room for doubt whether these 

 Bacteria are to be considered as normal products, or 

 as abnormal results (heterogeneous offcasts), brought 

 about by some unusual conditions acting upon the 

 parent fungus. That is to say, we may be doubtful 

 whether in such a case their origin ought to be con- 

 sidered Homogenetic or Heterogenetic. It may be 

 that many of the lower fungi are such changeable 

 organisms, and so prone to respond to the various 

 " conditions" acting upon them (which would be almost 

 certainly the case if they had been developed from a 

 Bacterium in two or three days the Bacterium itself 

 having been evolved de novo) that no very valid dis- 

 tinction can here be drawn between Homogenesis and 

 Heterogenesis Our whole point of view, in fact, con- 

 cerning such fungi as are seen to develop through 

 Leptothrix forms from Bacteria must be entirely 

 altered, if it is once conceded that Bacteria may arise 

 de novo. Such simple Mucedinece would then have to 

 be regarded as mere upstart organisms only a few 

 removes from dead matter, and in view of the greater 

 molecular mobility of living matter capable of being 



