COLLECTION AND IDENTIFICATION OF ROSES 949 
between and not upon the backs of the primary ones, the serration 
cannot be called “compound.” In compound serration the den- 
ticles may be one or several on the back of each primary tooth, or 
they may be found on the front 1. 
We have therefore the following classes :— 
{(a) Uniform. 
((0) Irregular. 
c) With a single denticle on the back of each 
1. Simple 
rimary tooth. 
9. Compound (2) With two or three denticles on the back of 
each primary tooth. 
(e) With denticles on both sides of the primary 
teeth. 
The difference between (a) and (d) or (e) is always clear and 
definite, but the adjacent subdivisions run into one another, and 
he same bush may present serration varying from (a) to (d). 
i 
botanists, some of whom form a subgroup of “ Transitorie 
between the Lutetiane and Dumales, but this does not help to 
Th 
appearance of the least quantity of hair on the midribs may cause 
the removal of an example from a group in which they should be 
glabrous, though it appears that too strict an adherence to this rule 
recognized, but no hard-and-fast line can really wn as to 
the amount and distribution. Its nature does not vary greatly, 
