156 JOURNAL OE THE ROYAL HORTICULTURAL SOCIETY 



Apricots. Primus Armeniaca. — The varieties cultivated in Great 

 Britain are not very numerous, and a few characteristics suffice to dis- 

 tinguish them. They have been classed in this way : 



A. Kernels bitter. 



x . Back of stone impervious (= not perforated). 

 Freestone. 

 Clingstone. 



x x . Back of stone pervious (= perforated). 

 Freestone. 

 Clingstone. 



B. Kernels sweet. 



Freestone. 

 Clingstone. 



It is a question whether the perforation of the stone would not be 

 a preferable character for the main divisions. The arrangement would 

 then be : 



A. Back of stone perforated. 



1. Kernels bitter. 



Freestone. 

 Clingstone. 



2. Kernels sweet. 



Freestone. 

 Clingstone. 



B. Back of stone not perforated. 



(Similar subdivisions.) 



Plums. Prunus communis. — Dr. Hogg's arrangement of Plums grown 

 in British gardens has never to my knowledge been surpassed. The 

 characters relied upon are readily available : namely, the smoothness or 

 hairiness of the young shoots, the shape of the fruit, the colour of the skin, 

 and the relation of the flesh to the stone (freestone and clingstone). 



The system in detail is as follows : 



A. Fruit round. 



1. Summer shoots smooth. 



x . Skin dark. 

 Freestone. 

 Clingstone, 

 x x . Skin pale. 

 Freestone. 

 Clingstone. 



2. Summer shoots downy. 



(Similar subdivisions.) 



B. Fruit oval. 



(The same subdivisions as in A.) 



Intermediate forms occur in all the sections, but as a general rule the 

 principal characters are easily applied. Perhaps the most difficult is in 

 the smoothness or downy state of the shoots, and it is rather puzzling 



