II. THE ORIGIN OF EACH NEW SPECIES CON- 

 SIDERED SEPARATELY. 



A. THE TWO OLDER SPECIES. 



§ 10. OENOTHERA LAEVIFOLIA. 



The reader will remember that amongst the Evening 

 Primroses in the field at Hilversnm there grew two new 

 species, 0. laevifolia and 0. brevistylis. These forms 

 have not been observed anywhere else before, so far as 

 I have been able to ascertain. It follows that they must 

 have arisen either on the spot (that is after 1870) or at 

 some period before the introduction of the parent species. 

 They have maintained themselves in the locality ever 

 since I began to observe them but there are no means 

 of telling whether a race of them has existed since they 

 first arose, or whether they have been produced by the 

 Lamarckiana from time to time. 



They have never arisen in my cultures. I have spent 

 much labor in looking for them ; but in vain. O. brevi- 

 stylis cannot possibly be missed if it is there and I have 

 carefully searched the plots for O. laevifolia. For ex- 

 ample in 1895 I looked through over one thousand flow- 

 ering plants of the Lainarckiana-iRmWy without seeing 

 a trace of a smooth leaved form. I repeated the search 

 in later years when I had many thousands of flowering 

 Oenotheras under cultivation. 



