XXVI. 



THE BATTLE OF THE PLUMS.' 



Every naturalist knows that there is a constant 

 struggle amongst animals and plants for a place in 

 which to live. This arises from the two facts that 

 more organisms are born than can find means or 

 place of subsistence, and that the circumstances or 

 the physical environments of life are constantly 

 changing. The struggle for existence operates in the 

 garden and nursery also, but it is frequently so pro- 

 foundly modified by many counter forces that it gen- 

 erally passes unrecognized. Every person who has 

 made any reflective study of horticulture knows that 

 varieties are coming and going, but the reasons for 

 this change are usually difficult to ascertain. It is 

 oftenest said, perhaps, that such change in varieties 

 is due to the direct and intelligent selection by man, 

 but it will generally be found, upon closer inquiry, 

 that his effort has really been guided by environments 

 and other circumstances which fundamentally affect 

 the species, and of which he may have had little 

 knowledge. In other words, the selection and im- 

 provement carried forward by the horticulturist may 

 be determined very largely by the same forces which 

 would have modified the subjects to a less degree. 



iRead before the Peninsula Horticultural Society, at Dover, Delaware, .Jan. 

 10,(1895. Printed in Transactions of the Society for 1895 (eighth annual meet- 

 ing), pp. 27-34. See, also, " Evolution of our Native Fruits." 



(418) 



