Experimental Pedigree-Cultures 559 



no struggle for existence are needed to reach 

 this end. In previous lectures I have mentioned 

 that I have saved the seeds of the mutants 

 whenever possible, and have always obtained 

 repetitions of the prototype only. Reversions 

 are as absolutely lacking as is also a further de- 

 velopment of the new type. Even in the case of 

 the inconstant f oinns, where part of the progeny 

 yearly return to the stature of lamarckiana, in- 

 termediates are not found. So it is also with 

 lata, which is pistillate and can only be prop- 

 agated by cross-fertilization. But though the 

 current belief would expect intermediates at 

 least in this case, thev do not occur. I made a 

 pedigree-culture of lata during eight successive 

 generations, pollinating them in different ways, 

 and always obtained cultures which were partly 

 constituted of lata and partly of lamarckiana 

 specimens. But the latas remained lata in all 

 the various and most noticeable characters, 

 never showing any tendency to gradually revert 

 into the original form. 



Intermediate forms, if not occurring in the 

 direct line from one species to another, might be 

 expected to appear perhaps on lateral branches. 

 In this case the mutants of one type, appearing 

 in the same year, would not be a pure type, but 

 would exhibit different degrees of deviation 

 from the parent. The best would then have to 



