714 Mutations 



points are in need of correction and elaboration, 

 but such improvements of our knowledge will 

 gradually increase our means of discovering 

 new instances and new proofs. 



The conception of mutation periods produc- 

 ing swarms of species from time to time, among 

 wMcb only a few have a chance of survival, 

 promises to become the basis for speculative 

 pedigree-diagrams, as well as for experimental 

 investigations. 



