566 Mutations 



feature: the minute differences in nearly all 

 points. 



V. The same new species are produced in a 

 large number of individuals. 



This is a very curious fact. It embraces two 

 minor points. The multitude of similar mutants 

 in the same year, and the repetition thereof in 

 succeeding generations. Obviously there must 

 be some common cause. This cause must be 

 assumed to lie dormant in the Lamarckianas of 

 my strain, and probably in all of them, as no 

 single parent-plant proved ever to be wholly 

 destitute of mutability. Furthermore the dif- 

 ferent causes for the sundry mutations must lie 

 latent together in the same parent-plant. They 

 obey the same general laws, become active under 

 similar conditions, some of them being more 

 easily awakened than others. The germs of the 

 oblonga, lata and nanella are very irritable es- 

 pecially, and are ready to spring into activity at 

 the least summons, while those of gigas, rubri- 

 nervis and scintillans are far more difficult to 

 arouse. 



These germs must be assumed to lie dormant 

 during many successive generations. This is 

 especially evident in the case of lata and nanella, 

 which appeared in the first year of the pedigree- 

 culture and which since have been repeated 

 yearly, and have been seen to arise by mutation 



