578 Mutations 



Are we to assume a single origin for all the 

 representatives of such a variety, as we have 

 done customarily for all the representatives of 

 a wild species ? Or can the same mutation have 

 been repeated at different times and in distant 

 localities! If a distinct mutation from a given 

 species is once possible, why should it not occur 

 twice or thrice? 



A variety which seems to be new to us may 

 only appear so, because the spot where it grows 

 had hitherto escaped observation. Lychnis 

 preslii is a smooth variety of Lychnis diurna 

 and was observed for the first time in the year 

 1842 by Sekera. It grew abundantly in a grove 

 near Miinchengratz in southern Hungary. It 

 was accompanied by the ordinary hairy type of 

 the species. Since then it has been observed to 

 be quite constant in the same locality, and some 

 specimens have been collected for me there late- 

 ly by Dr. N^mec, of Prague. No other native 

 localities of this variety have been discovered, 

 and there can be no doubt that it must have 

 arisen from the ordinary campion near the spot 

 where it still grows. But this change may have 

 taken place some years before the first discov- 

 ery, or perhaps one or more centuries ago. 

 This could only be known if it could be proved 

 that the locality had been satisfactorily investi- 

 gated previously, and that the variety had not 



