94 ACQUIRED CHARACTERS SEC. 



stations in which they had accustomed themselves to the pre- 

 vailing external conditions. That the trees themselves even 

 in the garden of Veitshochheim came from different stations 

 is a less probable supposition. 



We can observe every spring in our gardens that the shrubs 

 which belong to the south begin to bud later than our own 

 they are so accustomed to a certain slight degree of warmth 

 that it has no effect upon them ; their tissue is indifferent 

 towards this degree of warmth, is not stimulated by it. It 

 may thus be assumed that plants whose ancestors grew in cold 

 stations have become accustomed to cold, which means in 

 physiological terms that their tissues have gradually been 

 modified simply by the influence of climate. 



In this manner many of our cultivated plants have ac- 

 climatised themselves in a high degree. There cannot well 

 be any doubt that the different kinds of summer and winter 

 corn are forms which, originating from one and the same 

 species, have not only gradually accustomed themselves to 

 ripen at different times, but have also acquired new mor- 

 phological characters. Very remarkable instances of such 

 acclimatisation are described by F. C. Schiibeler in Scandi- 

 navian plants, especially species of cereals. 1 Schiibeler finds 

 that 



1. When various cereals in Scandinavia (Norway and 

 Sweden) are gradually transplanted from the plains to mount- 

 ain districts, they can be accustomed not only to develop in 

 the same, or even in a shorter time than in their native region, 

 but even at a lower average temperature. When such grain 

 after it has been grown for several years in the mountain 

 regions is again sown in its native soil, it ripens at first earlier 



1 F. C. Schiibeler, Viridarium Norvegicum.Xorges Vaxtrige. Et Bidrag til 

 Nord-Europas Natur- og Kulturhistorie. Bd. i. Universitets-Programm. With 

 numerous woodcuts iu the text, and four maps. Christiania (Dybwad) 1885. The 

 above extracts according to Foslie (Tromso), Botanisches Centralblatt, 1886. Bd. 

 xxviii. p. 205. 



