19, 
THE MOUNTAIN ASH. 
Pyrus aucuparia. 
Puate 3, Fie. 7. 
: (BE IMILARITY of leaf to the Com- 
y mon Ash has alone suggested the 
popular name of Pyrus aucuparia. 
It bears, however, no relationship 
to its namesake; and though the 
leaf, in the system of arrange- 
ment of its leaflets in opposite pairs on 
the rachis—or stem continuing the leaf- 
x *  stalk—and in its single leaflet at the 
termination of the rachis, bears a strong like- 
ness to Fravinus excelsior, the difference between 
the leaves of the two is discernible in the 
beautifully serrated edges of the leaflets of Pyrus 
