480 On the Latent Capacity for Mutation. 



Other new and old species were also much subject to 

 fasciatlon. For example in October 1899 they were par- 

 ticularly numerous in 0. hirtclla and some of its hybrids ; 

 many occurred amongst 0. lata and 0. albida in 1897; 

 and amongst 0. nanella in 1895. In one culture of O. 

 muricata in 1896 there were as many as 80%. fasciated 

 individuals; and in the cross O. muricata X 0. biennis 

 30% in 1896 and 25% in 1898; and so forth. 



These and other observations, not worth printing, 

 made in the garden and the field, seem to me to warrant 

 the conclusion that the capacity to produce fasciations 

 under suitable circumstances is heritable in a latent con- 

 dition in the genus Oenothera or at least in the group of 

 the bicnnis-speciQS (subgenus Onagra). 



Variegation of leaves. I only very seldom found 

 plants with yellow edged leaves — the first time was in 

 1887; otherwise the variegated leaves were streaked in 

 the ordinary way. I found two of these at Hilversum 

 in 1887 and two again in 1893; I sowed the seeds of 

 the former and got a single variegated plant amongst 

 m.any green ones in 1888. Some seeds collected at Hilver- 

 sum in 1888 gave one annual variegated plant. 



This abnormality also appeared in my cultures from 

 time to time. For example in the /a/a-family in 1888, 

 1890 and 1899; in the laez'ifolia-immly in 1889 (6 ex- 

 amples), 1891, 1894 and 1899. In the riibrinej'Z'is-iRmUy 

 in 1893 and 1894, in O. nanella in 1899 and amongst the 

 scintillans of 1890. 



The Lamarckiana-i3.mi\y gave two in 1888 and two 

 in 1890; the first two were annual and set seed, from 

 which I got a fair number of beautifully variegated 

 rosettes in the following year 1889. 



In the rubrinervis-idiVcnly there were occasional cases 



