OF ENVIRONMENT 141 



rial treatment with zinc sulphate is distinctly 

 discontinuous with the parent. 



5. Some of the modifications may be regarded 

 as an increase of capacities already present ; some 

 imply the loss of characters or structures, and 

 some are acquisitions ; in more than one instance 

 qualities new to the genus have been taken on. 

 Changes such as the mottling of a solidly col- 

 ored flower may be regarded as a loss of a por- 

 tion of a design, the total effect of which was a 

 shaded or a self color, or it may be taken as a 

 differentiation in advance. 



6. The behavior of the newly derived forms 

 when subjected to natural conditions, competi- 

 tion, and possibility of hybridization with paren- 

 tal forms, has been extremely diverse. Some of 

 the beetles have been swamped by hybridization 

 with the parental form; others have displayed 

 some power of endurance. The plant deriva- 

 tives induced by ovarial treatments were weaker 

 than the parent in some locahties, and more en- 

 during in others. The derivative of Oenothera 

 biennis induced by a zinc sulphate ovarial treat- 

 ment is less adapted to xerophytic conditions 

 than the parent, does not readily hybridize with 

 it when grown in contact, and its earlier char- 

 acters appear to be dominant when crosses are 

 made artificially. 



7. The departures obtained by the experi- 

 mental manipulation of external exciting agen- 

 cies bear a general similarity to the initiatory 



