452 



THE AMEBIC AN NATURALIST 



[Vol. XLVII 



formulated by the International Botanical Congress 

 held in Vienna in 1905. 



The effect of the separation of (E. Lamarckiana De 

 Vries from Lamarck's plant of about 1796 is to make far 

 more tangible the problem of its origin. In former 

 papers in the Naturalist (Davis, '11, p. 226; '12, p. 379) 

 I have criticized adversely the attempts that have been 

 made to place the appearance of Lamarckiana De Vries 

 in Europe at dates previous to 1778 when (E. grandiflora 

 Solander was introduced at Kew. In a recent contribu- 

 tion Grates ('13, pp. 17-19) admits that the presence of 

 Lamarckiana in Europe previous to 1760 is not estab- 

 lished and thus abandons his former position when he 

 sought to prove its very early introduction from Amer- 

 ica. With Lamarck's plant (CE. Lamarckiana Seringe) 

 removed from the discussion we are brought to periods 

 where we may hope for more direct evidence on the his- 

 tory of Lamarckiana De Vries than that furnished by 

 old accounts and figures. This matter will be further 

 discussed at the end of this paper in the section entitled, 

 "The Problem of the Origin of (E. Lamarckiana De 

 Vries. " 1 



The material of this paper will be arranged under the 

 following headings: (1) F 3 Generations in the Family 

 from the F 1 Hybrid 10.30La, (2) F 3 Generations in the 

 Family from the F, Hybrid 10.30L&, (3) Hybrids of 

 grandiflora B X biennis D in the F 2 Generation, (4) A 

 Discussion of the Behavior of the Hybrids in the Second 

 and Third Generations with Reference to the Stability 

 of Mendelian Factors, (5) The Habit of "Mutation" in 

 (E. Lamarckiana De Vries considered with Reference to 

 the Behavior of the Hybrids between biennis and grandi- 

 flora, (6) The Problem of the Origin of CE. Lamarckiana 

 De Vries. 



