SPORE CONDITIONS IN HYBRIDS AND THE MUTATION 



HYPOTHESIS OF DE VRIES 1 



Edward C. Jeffrey 



(with plates xxii-xxv) 



At the end of the sixteenth century Charles de l'Ecluse 

 became professor of botany in the University of Leyden. He 

 brought with him from Vienna to his new abode plants of the tulip, 

 which had been introduced from Turkey into southeastern Europe. 

 These formal plants he cultivated with great success in his own 

 garden, and was fortunate in arousing a keen and even commercial 

 interest among the phlegmatic Dutch; so much so that when the 

 excitement was at its height, his garden was invaded and many 

 of his choicest varieties stolen. Thus arose the famous "Tulipo- 

 mania," which has been immortalized by Dumas. Three hundred 

 years later another Dutch botanist has become the author of 

 another botanical sensation, which will doubtless also live in history. 

 Professor De Vries has initiated the investigations on the genus 

 Oenothera in connection with the hypothesis of mutation or 

 saltatory origin of species. His discovery first that Oenothera 

 Lamarckiana and subsequently that other species of the genus 

 are capable of producing distinct so-called elementary species when 

 cultivated on a large scale has very properly attracted a great deal 

 of attention, particularly in the continent of North America, which 

 prides itself, not altogether without reason, on its openness to new 

 ideas. Thus it has come about that the genus Oenothera, and in 

 particular O. Lamarckiana, has become the battleground of the 

 mutation hypothesis on the botanical side. We have had during 

 the past decade a veritable " Oenotheromania " comparable to 

 the " Tulipomania " of three centuries ago. 



There have been many objections raised to the mutation 

 hypothesis of De Vries, particularly on the part of geneticists of 



1 Contributions from the Phanerogamic Laboratories of Harvard University, 



no. 70. 



Botanical Gazette, vol. 58] 



[322 



