XXVI.] THE ADVENT OF THE JAPANESE TYPE. 427 



digenous fungous or insect enemies in other native 

 plants. It is best marked in the grapes, which are 

 not seriously injured by phylloxera or downy mildew, 

 both of which are indigenous troubles, whilst the 

 European grape is very quickly decimated by them. 

 The pear blight is a similar instance. It is an 

 American disease which, before the introduction of 

 European fruits, probably lived upon the wild thorn 

 apples, but the pear and quince are less able to resist 

 its attack. The peach yellows is also an American 

 disease which thrives upon an imported host, and I 

 am expecting every year to hear that some one has 

 discovered it upon its original native plant. 



But a new factor has now come into this complex 

 battle of the plums. A Japanese type has been intro- 

 duced within the last quarter century, and, contrary 

 to the expectations of its most sanguine admirers, 

 it has proved to be well adapted to a much wider 

 range of our country than the European type is. And, 

 strangely enough, it is now found that this oriental 

 species is more closely related to our native species 

 than to the European. This fact was first noticed by 

 horticulturists, who discovered that the winter twigs 

 and buds of the Japanese and Wild Goose types are 

 often so much alike that they may be almost indis- 

 tinguishable when mixed in the same bundle. It was 

 only a year ago this very month that these similari- 

 ties and some explanations of their origin were first 

 published. The gist of the matter is this : It was 

 long ago shown by the late Asa Gray that the floras 

 of Japan and eastern North America are very similar, 

 due to the persistence of similar types of post-glacial 

 plants in regions of similar geographical jjosition and 



