574 Mutations 



biennial. Some are rich in pollen, while scin- 

 tillans is poor. Some have large seeds, others 

 small. Lata has become pistillate, while 

 brevistylis has nearly lost the faculty to pro- 

 duce seeds. Some undescribed forms were 

 quite sterile, and some I observed which pro- 

 duced no flowers at all. From this statement it 

 may be seen that nearly all qualities vary in op- 

 posite directions and that our group of mutants 

 affords wide material for the sifting process of 

 natural selection. On the original field the 

 laevi folia and brevistylis have held their own 

 during sixteen years and probably more, with- 

 out, however, being able to increase their num- 

 bers to any noticeable extent. Others perish 

 as soon as they make their appearance, or a 

 few individuals are allowed to bloom, but prob- 

 ably leave no progeny. 



But perhaps the circumstances may change, 

 or the whole strain may be dispersed and spread 

 to new localities with different conditions. Some 

 of the latter might be found to be favorable to 

 the robust gig as, or to rubrinervis, which re- 

 quires a drier air, with rainfall in the spring- 

 time and sunshine during the summer. It would 

 be worth while to see whether the climate 

 of California, where neither 0. lamarckiana 

 nor 0. biennis are found wild, would not exactly 



