ADAPTATION 195 



is bred in captivity these irregularities of behaviour do or do not 

 occur when the larvae are fed on uninjured leaves. 



The famous case of Schiibeler's wheat is revived by Semon. 

 The story will be familiar to most readers of the literature of the 

 subject. Briefly it is that annuals, especially wheat and maize, 

 raised from seed in Central Europe take more time in coming 

 to maturity and ripening than similar plants raised in Norway, 

 where the summer days are much longer. The received account 

 is that he imported seed especially of maize and of wheat from 

 Central Europe to Norway and found that in successive years 

 the period of growth and ripening was increasingly reduced. 

 After two generations seed of the accelerated wheat was sent 

 back to Breslau where it was grown, and was found to ripen rather 

 more slowly than in Norway, but much more quickly than the 

 original stock had done. The facts recorded by Schlibeler 6 are 

 that he received seed from Eldena, which is on the Baltic near 

 Greifswald. The variety is described as " 100 tdgiger Sommer 

 Weizen" but no more exact record of its behaviour in Germany 

 is given. This wheat, grown at Christiania in 1857, took 103 

 days to harvest. Its seed was again grown in Christiania in 1858, 

 and took 93 days, and sown again in 1859 it took only 75 days, 28 

 days less than in the first year of cultivation in Norway. Seed of 

 the 1858 crop was sent to Breslau, and grown there by Roedelius 

 in 1 859; it took 80 days. Evidently before such a record can be 

 used as proving an inheritance of acquired characters numbers of 

 particulars should be forthcoming. The view that Johannsen 

 has taken is that the result was probably due to unconscious 

 selection of the earlier individuals among a population consisting 

 of many types of various compositions. Some effect may no 

 doubt be ascribed to that cause, but I cannot think that alone 

 it would account for the results. My impression is rather that 

 they were produced by differences in the cultivation and especially 

 in the seasons. Research of an elaborate character would be 

 necessary in order to eliminate the various sources of error, and 

 nothing of the kind has been done; nor does Semon allude to these 

 difficulties in prominently adducing Schiibeler's evidence. A 



6 Schiibeler, F. C., Die Culturpflanzen Norwegens, 1862, especially pp. 24 and 28. 



