Mutations in Horticulture 617 



ascribed by some authors to the fact that often 

 on the same tree the male catkins flower and fall 

 off several weeks before the ripening of the 

 pistils of the other form of flowers. 



Weeping varieties afford similar instances. 

 Sophora japonica pendula originated about 

 1850, and Gleditschia triacanthos pendula some 

 time later in a nursery at Chateau-Thierry 

 (Aisne, France). In the year 1821 the bird's 

 cherry, or Prunus Padus, produced a weeping 

 variety, and in 1847 the same mutation was ob- 

 served for the allied Prunus Mahaleb. Numer- 

 ous other instances of the sudden origin of 

 weeping trees, both of conifers and of others, 

 have been brought together in Korshinsky's 

 paper. This striking type of variation includes 

 perhaps the best examples of the whole his- 

 torical evidence. As a rule they appear in large 

 sowings, only one, or only a few at a time. Many 

 of them have not been observed during their 

 youth, but only after having been planted out 

 in parks and forests, since the weeping charac- 

 ters show only after several years. 



The monophyllous bastard-acacia originated 

 in the same way. Its peculiarities will be dealt 

 with on another occasion, but the circumstances 

 of its birth may as well be given here. In 1855 

 in the nursery of Deniau, at Brain-sur-1'Au- 

 thion (Maine et Loire), it appeared in a lot of 



