MUTATIONS, VARIATIONS, AND RELATIONSHIPS OF THE OENOTHERAS. 31 



This work was not begun until late in the season, the first collection of buds 

 for this study having been made on September 15 and the last on October 30, 

 and this will need to be taken into account in making future comparisons, 

 though it seems likely that the periodicity is too slight to make this a modify- 

 ing factor of any considerable moment. 



The number of buds from each lot of specimens, except one, was from 140 

 to 161. In Oenothera gigas only 91 buds were secured before frost cut short 

 the investigation. The lateness of the time at which the work was begun 

 prevented the measurement of a larger number of buds of each lot, though it is 

 realized that a much larger number would be desirable. On this account it 

 is not thought necessary to present variation curves of each lot of measure- 

 ments. Instead, the constants have been calculated and are presented in the 

 form of a table : 



*d = Oenothera lamarckiana from lot 



