PLUMS RIPEK. 197 



by cattle, deer, or antelopes. It is this southern variety 

 that was first taken in hand by man as a garden fruit ; 

 for almost all our common cultivated plants come to us, 

 with the rest of our civilization, from the central Asian 

 and Mediterranean region. The little bullace now most 

 nearly resembles the wild southern stock, and it has been 

 discovered and recognized among the rubbish-heaps of 

 the Swiss Lake villages ; so that its cultivation is at least 

 as old as the later stone age, and probably far older, for 

 it appears even then as a distinctly cultivated and im- 

 proved variety. Still, these very ancient bullaces are 

 considerably smaller than the smallest garden plums of 

 the present day, as is always the case with fruits and 

 seeds found under similar circumstances. 



By dint of long selection our modern plum-trees have 

 lost their thorns, doubtless because the thorny specimens 

 were disagreeable to the pickers, so that any stray thorn- 

 less sport would be sure to obtain a preference and be 

 used as the chosen parent of future varieties. To be 

 sure, the gooseberry-bush has not yet lost its prickles ; 

 but then the gooseberry is a comparatively recent fruit in 

 cultivation, hardly dating back much further in time 

 than some ten centuries, whereas the plum has been 

 grown by man for a practically immemorial period. 

 Under stress of tillage, the original bullace has been once 

 more distributed into the various types of damsons, 

 greengages, Orleans plums, and golden drops, which 

 differ from one another in their fruit far more than the 

 bullace itself differs from the wild sloe of southern 

 Europe. Indeed, seeing that all these markedly distinct 

 varieties have been demonstrably produced within quite 

 recent times from a single common ancestor, it is not 

 difficult to understand how that ancestor itself may have 

 been produced at a still earlier age from the central 



