208 COLIN CLOUTS CALENDAR. 



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 imme- 

 morial 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 demon- 

 strably produced within quite recent times from 

 a single common ancestor, it is not difficult to under- 

 stand how that ancestor itself may have been pro- 

 duced at a still earlier age from the central parent stock 

 of all the plums, apricots, and cherries. What nature 

 thus did before by her slow selection, man has merely 

 continued to do more rapidly by his quicker and exclu- 

 sive methods. Only, man concentrates his attention on 

 one single point alone the succulent fruit ; nature 

 equally favours every useful variation in stem, leaf, flower, 

 fruit, or seed alike. Hence it happens that while the 

 wild cherry differs slightly from the blackthorn in almost 

 every particular, the greengage differs from the damson 

 almost exclusively in the fruit, every other part remain- 

 ing essentially identical. If cultivated plums are 

 allowed to sow themselves and run wild at the present 

 day, they retain their tree-like form, but revert rapidly 

 to the bullace type. If long permitted to continue wild, 

 however, they show a tendency at last to go back even 

 to the parent south European blackthorn. Their ac- 

 quired habits are not yet sufficiently ingrained in the 

 race to constitute them a good and permanent species. 



