THE APPLE, PEAR, AND QUINCE. 161 



records in the city of Bokhara. Such facts indicate that 

 Henfrey was right in assuming two natural centres of 

 plant distribution on the eastern continent, one in west 

 Europe and the other in east Europe and north central 

 Asia. 



The fact can be sustained that most of the apples of 

 west Europe and the United States and Canada are 

 mongrels. They may in a broad sense all belong to one 

 species, but they are a mingling of races. The close 

 observer can find in France, Germany, and over west 

 Europe dozens of varieties introduced from east Europe 

 and many dozens of varieties that show in leaf, bud, and 

 color and bloom of fruit traces of European and Asiatic 

 crossing with the t} r pical west European Pyrus mains. 

 In the United States it is a suggestive fact that what are 

 called the iron-clad varieties in the North and Northwest 

 all show the birth-marks of direct introduction or descent 

 from the type or race which London classed as Pyrus 

 Astraclianica. Even such standard varieties as Ben Davis, 

 Gano, Baldwin, and Westfield seeknofurther show in 

 leaf, tree, and fruit an admixture with the anciently culti- 

 vated varieties of east Europe and central Asia. 



In the same way it is not wholly correct to say that our 

 Siberian crabs are all derived from the Pyrus baccata of 

 Siberia. In 1882 we found in far east Europe varieties of 

 crab-apple with fruit growing in clusters quite as large as 

 the hyslop or transcendent, with large leaves as fuzzy on 

 the under side as the wild Pyrus mains of west Europe. 

 The well-known Virginia crab belongs to this race, and we 

 have reason to believe that several of our large crabs that 

 fruit in clusters are crosses of this race with the Siberian 

 crab. It is not as easy to secure crosses between the 

 Pyrus baccata and the common apple as is usually sup- 

 posed. Thomas Andrew Knight, of England, carried on 



