ROSACEOUS FRUITS ] 185 



grafted on its own seedlings, on the plum and on the 

 almond. The cherry, like the service tree among the 

 kernel fruits, is less accomodating being grafted only on 

 its seedlings or suckers, and on species of wild cherry. 

 The stone fruits (tribe Amygdaleae) produce their 

 flowers singly, that is each flower is usually in separate 

 buds, or there may be two flowers in one bud, and the 

 fruit consists of the fertilized superior ovary, and 

 contains only one hard-shelled locule, or stone, enclosing 

 one or sometimes two seeds. These fruit trees show 

 their relationship also by their common liability to certain 

 diseases, and by the fact that they all exude gum from 

 wounds in the bark of the stem and branches. 



A feature common to all rosaceous fruits, including 

 strawberries and other small fruits, is that when they 

 die they all leave a peculiar poison in the soil owing 

 to which any rosaceous tree planted to replace them, 

 cannot thrive well, and generally dies as soon as it 

 has established itself properly, that is as soon as its 

 roots have reached the dead and rotten roots of the 

 former tree. This poison often lasts for a considerable 

 time, sometimes as much as ten years or more, and 

 persists for a longer period when the dead tree has 

 been a large one. The poison seems to be more 

 virulent on lands which are not well drained, but its 

 action in a cool and moist locality is much the same as 

 in a dry and sunny one. Not all rosaceous fruits are 

 affected by this poison to the same extent. Of the 

 kernel fruits, the quince seems to be the most susceptible, 

 and of course the pear grafted on the quince suffers 

 to the same extent. On the other hand, the pear 

 growing on pear stock is the most resistant of all 

 kernel fruits. The almond, particularly the bitter almond, 

 is the most resistant of the stone fruits and perhaps 

 also of all rosaceous fruits, but when the almond is 

 used as stock for the peach it loses much of this 

 power of resistance, and becomes weaker still when 



