282 University of California Publications. [Botany 



the amount of variation, which is quite the same as in groups 

 where sexual reproduction occurs. 



In conclusion I wish to acknowledge my gratitude to Prof. 

 W. J. V. Osterhout, under whose direction the work has been 

 performed, for many helpful suggestions; and to Prof. W. A. 

 Setchell for the determination of the specimens considered in this 

 paper. 



