278 The Pedigree Families. 



family originated from the seed collected near Hilversum 

 in 1887. Since 1894 O. laevifolia has always been arti- 

 ficially self-fertilized, and since that date it has ceased to 

 mutate. 



§ /. TWO LATA-FAMILIES. 



Oenothera lata is one of that group of my new spe- 

 cies which have arisen most abundantly from O. La- 

 marckiana. It is also the oldest, appearing, as it did, 

 as early as 1887 in my garden from the seeds gathered 

 near Hilversum. In the following year it also arose from 

 the seeds of the biennial plants which are mentioned in 

 § 1 on page 220 as forming the first generation of my 

 chief experiment. 



From these two mutations I have derived two sep- 

 arate families, one of which I cultivated till 1890, whilst 

 the other has with occasional interruptions been con- 

 tinued to the present day (1900). 



Oenothera lata is, as has been already stated, solely 

 female. If it is to bear seed it must be fertilized bv 

 other species. I fertilized it in 1887 with the pollen of 

 Lamarckianas arising from the same sample of seed. 

 From this cross I got in the following year some latas and 

 some Lamarckianas, the former in the proportion of from 

 15 to 20 %.i From that time until 1894 I had the two 

 forms growing together and left them to be fertilized by 

 insects ; since then I have enclosed the flowers of lata 

 in parchment bags and fertilized them myself. The 

 pollen I have used has either been from Lamarckiana 

 with the same mothers as the latas in question, or from 

 Lamarckianas of other ancestry. 



^ Ueber erhiingleiche Kreuzun^en, Ber. d. d. Bot. Ges.. Nov. 

 1900, Bd. XVTII, p. 435. 



